SOLUTION: (5x+4)^2=100

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Question 188517: (5x+4)^2=100
Found 2 solutions by jim_thompson5910, feliz1965:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

%285x%2B4%29%5E2=100 Start with the given equation.


5x%2B4=0%2B-sqrt%28100%29 Take the square root of both sides.


5x%2B4=sqrt%28100%29 or 5x%2B4=-sqrt%28100%29 Break up the "plus/minus" to form two equations.


5x%2B4=10 or 5x%2B4=-10 Take the square root of 100 to get 10.


5x=-4%2B10 or 5x=-4-10 Subtract 4 from both sides.


5x=6 or 5x=-14 Combine like terms.


x=6%2F5 or x=-14%2F5 Divide both sides by 5 to isolate x.


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Answer:


So the solutions are x=6%2F5 or x=-14%2F5.

Answer by feliz1965(151) About Me  (Show Source):
You can put this solution on YOUR website!
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?