Question 33617
use this expression the help you greatly: ar^2 + br + c
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4r2(the 2 is the exponent) + 3r - 10
4r^2 + 3r -10 find factors of ac that add up to b
so............. ac in this problem is -40; know, find factors of -40 that adds up to 3........ the two factors are 8,-5
4r^2 + 8r - 5r - 10 use the two factors as r
(4r^2 + 8r) + (-5r - 10) group the problem
4r(r + 2) - 5(r + 2) take out the common factors
(4r - 5)(r + 2) your answer