McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
9. Perfect Squares
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Exercise 55 Page 70

Write a perfect square trinomial. Then, place the negative sign and the fraction where requested. To solve it write it as a perfect square and take the square root of each side.

Example Equation: 4x^2 - 3x + 916 = 0
Solution: 38

Practice makes perfect
A perfect square trinomial equation in which the middle term is negative and the last term is a fraction looks as follows. ( ax)^2 - 2( ax)(b/c) + (b/c)^2 = 0 In the equation above a, b, and c are any real numbers and b and c have no common factors. Let's pick, for example, a= 2, b= 3, and c = 4. ( 2x)^2 - 2( 2x)(3/4) + (3/4)^2 = 0 ⇓ 4x^2 - 3x + 9/16 = 0 The final equation is the one we were requested to find. Next, let's solve this equation for x.
4x^2 - 3x + 9/16 = 0
2^2x^2 - 3x + 3^2/4^2 = 0
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Simplify left-hand side
(2x)^2 - 3x + 3^2/4^2 = 0

a^m/b^m=(a/b)^m

(2x)^2 - 3x + (3/4)^2 = 0
(2x)^2 - 2(2x)(3/4) + (3/4)^2 = 0
(2x - 3/4)^2 = 0
To continue solving the equation, we can take the square root of each side.
(2x - 3/4)^2 = 0
2x - 3/4 = ± 0
2x = 3/4
x = 3/8
In conclusion, the solution to the equation we wrote is x= 38. Keep in mind that the equation presented above is just an example and your answer may vary.