2x2 - 13x + 15 =0
divide through by 2: ==> x2 - (13/2)x + 15/2 = 0
subtracting 15/2 from both sides:==> x2 -(13/2)x = -15/2
Take half the coefficient of x, square it and add to both sides.
==> x2 - (13/2)x + (13/2)2
= -15/2 + 169/16
=(-120 + 169)/16
Write LHS as perfect square ==> (x - 13/4)2 = 49/16
Take square root of both sides: x - 13/4 = + - 7/4
x = 13/4 + - 7/4
= 20/4 or 6/4
= 5 or 1.5
Githiari answered the question on April 3, 2019 at 17:30
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