Give that x= 4 is a root of x²+kx-20=0. Find the value of k and thus other roots

Answers

Kavungya answered the question on September 20, 2019 at 05:59

Next: Copy and complete the table below for the function y=4+5x-x² for -2=x=7
Previous: If ? is an acute angle find the value of Cos ? in the panating: 4 Sin²?-5 Cos ?+2=0

View More Mathematics Questions and Answers | Return to Questions Index

Exams With Marking Schemes

Related Questions

Copy and complete the table below for the function y=4+5x-x² for -2=x=7(Solved)
Copy and complete the table below for the function y=4+5x-x² for -2≤x≤7

Date posted: September 20, 2019. Answers (1)
A supermarket is stocked with plates which come from two suppliers A and B. They are bought in the ratio of 3:5 respectively, 10% of...(Solved)
A supermarket is stocked with plates which come from two suppliers A and B. They are bought in the ratio of 3:5 respectively, 10% of plates from A are defective and 6% of the plates from B are defective.
(a) A plate is chosen by a buyer at random. Find the probability that;
(i) it is from A
(ii) it is from B and it is defective.
(iii) it is defective
(b) Two plates are chosen at random. Find the probability that:
(i) both are defective
(ii) at least one is not defective.

Date posted: September 20, 2019. Answers (1)
The points X and Y are both on latitude 39^oN. The longitude of X is 73^oW and the longitude of Y is 18^oW . Two...(Solved)
The points X and Y are both on latitude 39^oN. The longitude of X is 73^oW and the longitude of Y is 18^oW . Two ships P and Q leave X at the same time and travel to Y along the line of latitude. The ships P and Q travel at constant speeds of 25km/hr and 20km/h respectively. Taking the radius of the earth to be 6371km and π= 22/7 ;Calculate:-
(a) The distance Q still has to travel when P reaches Y.
(b) At the same time a third ship R leaves Y traveling due west at an average speed of 15km/hr.
Calculate the longitude of the point at which R meets P.

Date posted: September 20, 2019. Answers (1)
In a square PQRS, A is the mid-point of PQ and B is the mid-point of QR, while C is a point on BP such...(Solved)
In a square PQRS, A is the mid-point of PQ and B is the mid-point of QR, while C is a point on BP such that 2BC = 3CP. The co-ordinates of P, Q and S are (4,4), (14,4) and (4,14) respectively. Find:
(a) (i) the column vectors of PQ and PS.
(ii) co-ordinates of R
(b) Show that A, C, S are collinear.

Date posted: September 20, 2019. Answers (1)

The n^th term of a series is given by 3n+4. (a) Write down the first four terms of the series. (b) Find the sum of the first...(Solved)
The n^th term of a series is given by 3n+4.
(a) Write down the first four terms of the series.
(b) Find the sum of the first twenty terms of the series.
(c) Find the 30^th term.
(d) Show that the sum of the first n terms of the sequence is given by S_n=3/2n²+11/2n. Hence or otherwise, find the largest integral value of n such that Sn ≥130.

Date posted: September 20, 2019. Answers (1)
Find the equation of the tangent to the circle x²+y²-8x+2y+7=0 at the point (3, 2). Give your answer in the form y=ax+b. (Solved)
Find the equation of the tangent to the circle x²+y²-8x+2y+7=0 at the point (3, 2). Give your answer in the form y=ax+b.

Date posted: September 19, 2019. Answers (1)
Without using mathematical tables and calculators simplify:(Solved)
Without using mathematical tables and calculators simplify:

Date posted: September 19, 2019. Answers (1)
In the figure below, AB is a tangent, meeting chord CDE at B. DE=xcm Determine: (a) the value of x (b) the length of AB (Solved)
In the figure below, AB is a tangent, meeting chord CDE at B. DE=xcm

Determine:
(a) the value of x
(b) the length of AB

Date posted: September 19, 2019. Answers (1)

PQRS is a cyclic quadrilateral in which PQ=6cm, QR=2cm, RS=6.5cm, PR=7.2cm and angle PRS=70^o. Determine values of x.(Solved)
PQRS is a cyclic quadrilateral in which PQ=6cm, QR=2cm, RS=6.5cm, PR=7.2cm and angle PRS=70^o.

Determine values of x.

Date posted: September 19, 2019. Answers (1)
Use matrix method to solve simultaneous equations. 3x + 7y = 11 x – y + 4 = 0 (Solved)
Use matrix method to solve simultaneous equations.
3x + 7y = 11
x – y + 4 = 0

Date posted: September 19, 2019. Answers (1)
The distance between Sotik and Nakuru is 130km. car x starts from Sotik at 8.00 a.m and travels at 40km/hr towards Nakuru. A second car...(Solved)
The distance between Sotik and Nakuru is 130km. car x starts from Sotik at 8.00 a.m and travels at 40km/hr towards Nakuru. A second car y starts traveling from Nakuru at 8.15 a.m towards Sotik at an average speed of 35km/hr. At what time will the two cars meet?

Date posted: September 19, 2019. Answers (1)
A variable P varies as the square of Q and inversely as square root of R. Find the percentage change in P when Q is...(Solved)
A variable P varies as the square of Q and inversely as square root of R. Find the percentage change in P when Q is increased by 5% and R reduced by 19%.

Date posted: September 19, 2019. Answers (1)
Make C the subject of the formula.(Solved)
Make C the subject of the formula.

Date posted: September 19, 2019. Answers (1)
(a) Expand and simplify the expression (10+2/x)⁵ (b) Use the expression in (a) above to find the value of 14⁵. (Solved)
(a) Expand and simplify the expression (10+2/x)⁵
(b) Use the expression in (a) above to find the value of 14⁵.

Date posted: September 19, 2019. Answers (1)
The table below is part of tax table for monthly income for the year 2010. Monthly taxable income in Ksh. Tax rate % in...(Solved)
The table below is part of tax table for monthly income for the year 2010.
Monthly taxable income in Ksh. Tax rate % in each sh.
Under Ksh. 9681 10%
From Ksh. 9681 but under 18801 15%
From Ksh. 18801 but under Kshs.27921 20%
In the year 2010, the tax on Koech’s monthly income was Ksh.1916. Calculate Koech’s monthly income.

Date posted: September 19, 2019. Answers (1)
Evaluate:(Solved)
Evaluate:

Date posted: September 19, 2019. Answers (1)
Use logarithms in all steps to evaluate:(Solved)
Use logarithms in all steps to evaluate:

Date posted: September 19, 2019. Answers (1)
The two variable P and Q are connected by Q=K(a^p) and the table of values of P and Q is given below. (a) Write the equation...(Solved)
The two variable P and Q are connected by Q=K(a^p) and the table of values of P and Q is given below.

(a) Write the equation Q=K(a^p) in the form y = mx + c.
(b) Draw the linear graph.
(c) Find the value of a and k.
(d) Write the equation connecting Q and p.

Date posted: September 19, 2019. Answers (1)
In the figure below O is the centre of the circle and PTQ is the tangent at T. If PT=ST and angle SRT=52^o. Determine the...(Solved)
In the figure below O is the centre of the circle and PTQ is the tangent at T. If PT=ST and angle SRT=52^o. Determine the size of the angles below giving reasons:

(a) PTS
(b) RTQ
(c) TSR
(d) TQR
(e) PSQ

Date posted: September 19, 2019. Answers (1)
Find the number of terms in the series a+3a+9a+……………….+243a . (Solved)
Find the number of terms in the series
a+3a+9a+……………….+243a .

Date posted: September 19, 2019. Answers (1)