<PRE><B>Question 188517</B>
I will set it up and you can take it from there.

(5x + 4)^2 = (5x + 4)(5x + 4) 

(5x + 4)(5x + 4) becomes 25x^2 + 40x + 16 using FOIL. 

We now equate to 100.

25x^2 + 40x + 16 = 100

Subtract 100 from both sides of the equation to make a quadratic equation.

25x^2 + 40x + 16 - 100 = 0

25x^2 + 40x + 84 = 0

Can you take it from there?





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