Question

$show \: that \: (x + 5) \: is \: a \: factor \: of \: {2x}^{3} + 9 {x}^{2} - 11x - 30$
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Answer 1

Solution

Given:- (x+5) is a factor of given equation 2x³ + 9x² - 11x - 30

x + 5 = 0

x = -5

2x³ + 9x² - 11x - 30

=> 2(-5)³ + 9(-5)² - 11(-5) - 30

=> 2(-125) + 9(25) + 55 - 30

=> -250 + 225 + 25

=> -250 + 250

=> 0

Hence proved, (x + 5) is the factor of given equation.