McGraw Hill Integrated II, 2012
MH
McGraw Hill Integrated II, 2012 View details
1. Solving Quadratic Equations by Factoring
Continue to next subchapter

Exercise 2 Page 174

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

Example Solution: 8x^2-14x+3=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 32 and 14, we can partially write the factored form of our equation. a( x- 3/2 ) ( x-1/4 )=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=8. This is a common multiple of both denominators of the given roots and will allow us to eliminate the fractions when we distribute. 8( x- 3/2 ) ( x-1/4 )=0 Finally, let's use the Distributive Property to obtain the standard form.

8( x- 3/2 ) ( x-1/4 )=0
â–¼
Distribute 8
2(4)( x- 3/2 ) ( x-1/4 )=0
2( x- 3/2 ) (4)( x-1/4 )=0
( 2x- 3 ) (4)( x-1/4 )=0
(2x-3) (4x-1)=0
â–¼
Multiply parentheses
2x(4x-1)-3(4x-1)=0
8x^2-2x-3(4x-1)=0
8x^2-2x-12x+3=0
8x^2-14x+3=0

Please note that this is just one example of a quadratic function that satisfies the given requirements.