Given (1 – 3x)⁵ Determine the number of terms in the expansion

Given (1 – 3x)⁵
a) Determine the number of terms in the expansion
b) Expand (1 - 3)⁵ and use your expansion to estimate (0.97)⁵ correct to 4 significant figures

Answers

a) There are 6 terms

b) (1 -3x)⁵

=1⁵ + 5(1) )⁴(-3x) )¹+10(1) )³(-3x) )² + 10(1) )²

(-3x) )³ + 5(1) )¹(-3x) )⁴ + (-3x) )⁵

Simplify completely

=1-5x + 90x)² - 270)³ + 405x)⁴ - 243x)⁵

3x = 0.03; x = 0.01

Substitute in the

Expansion above to get

= 1 – 15(0.01) + 90(0.01) )² - 270 (0.01)³ +

= 1 – 0.15 + 0.009 – 0.00027 +…..

= 0.8587

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johnmulu answered the question on March 8, 2017 at 09:34

Next: Solve the equation log₃(x + 23) - log₃(log₂32) = log₃(9 - 2x)
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