McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
Study Guide and Review
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Exercise 69 Page 84

Be sure that all of the terms of are on the same side and in the correct order for the standard form of a quadratic function.

- 5, 5

Practice makes perfect
To solve the given equation by factoring, we will start by identifying the values of a, b, and c. a^2-25=0 ⇔ 1a^2+ 0a+( - 25)=0 Notice that this equation follows a special pattern. It can be factored as a difference of squares. Let's factor the equation!
a^2-25=0
a^2-5^2=0
(a+5)(a-5)=0
Now we are ready to use the Zero Product Property.
(a+5)(a-5)=0
â–Ľ
Solve using the Zero Product Property
lca+5=0 & (I) a-5=0 & (II)
la=- 5 a-5=0
la=- 5 a=5
We found that the solutions to the given equation are a=- 5 and a= 5. To check our answer, we will graph the related function f(a)=a^2-25 using a calculator. Note that the calculator will use the variable x instead of a.

We can see that the x-intercepts are - 5 and 5. Therefore, our solutions are correct.