Question

if one of the factor of x square + x- 20 is ( x+5) find the other
a) x - 4 b) x - 5. c) x- 1
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Answer 1

Step-by-step explanation:

${x}^{2} + x - 20$

$= {x}^{2} + (5 - 4)x - 20$

$= {x}^{2} + 5x - 4x - 20$

$= x(x + 5) - 4(x + 5)$

$= (x + 5)(x - 4)$

The other factor is (x-4).