How do you factor #9x ^ { 2} + 31x - 20#?

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Answer 1 · 2018-07-11T05:41:12

#(9x-5)(x+4)#

Given -

#9x^2_31x-20#

Find the product of -20 and 9.

It is -180

Find two numbers, the total of the two numbers must be equal to 31 and the product of these two numbers must be equal to 180.

The two numbers are 36 and -5.

The write the #31x# term as #36x-5x# and rewrite the equation.

#9x^2+36x-5x-20#

#9x(x+4)-5(x+4)#

#(9x-5)(x+4)#