McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
1. Solving Quadratic Equations by Factoring
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Exercise 58 Page 175

Use the given roots to write the equation in factored form. Then multiply and simplify to obtain the standard form.

Example Solution: 99x^2-73x+10=0

Practice makes perfect
We can write a quadratic equation in factored form using the given roots. Then we will change it to standard form by multiplying the factors. Factored Form:& a(x-p)(x-q)=0 Standard Form:& ax^2+bx+c=0 In the factored form, p and q are the roots of the equation. Since we are told the roots are 211 and 59, we can partially write the factored form of our equation. a( x- 2/11 ) ( x-5/9 )=0 Since a does not have any effect on the roots, we can choose any value. For simplicity and in order to have integer coefficients, we will let a=99. This is a common multiple of both denominators of the given roots and will allow us to eliminate the fractions when we distribute. 99( x- 2/11 ) ( x-5/9 )=0 Finally, let's use the Distributive Property to obtain the standard form.
99( x- 2/11 ) ( x-5/9 )=0
â–Ľ
Distribute 99
99( x- 2/11 ) ( x-5/9 )=0
11( x- 2/11 ) (9)( x-5/9 )=0
(11x-2)(9)( x-5/9 )=0
(11x-2)(9x-5)=0
â–Ľ
Multiply parentheses
11x(9x-5)-2(9x-5)=0
99x^2-55x-2(9x-5)=0
99x^2-55x-18x+10=0
99x^2-73x+10=0
Please note that this is just one example of a quadratic function that satisfies the given requirements.