Big Ideas Math Geometry, 2014
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Big Ideas Math Geometry, 2014 View details
5. Angle Relationships in Circles
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Exercise 41 Page 568

Make sure you write all the terms on the left-hand side of the equation and simplify as much as possible before using the Quadratic Formula.

x_1=3 and x_2=- 4

Practice makes perfect
We will use the Quadratic Formula to solve the given quadratic equation. ax^2+ bx+ c=0 ⇕ x=- b± sqrt(b^2-4 a c)/2 a Let's start by rewriting the equation so all of the terms are on the left-hand side. x^2+x=12 ⇓ x^2+x-12=0 Now we can identify the values of a, b, and c. x^2+x-12=0 ⇕ 1x^2+ 1x+( - 12)=0 We see that a= 1, b= 1, and c= - 12. Let's substitute these values into the Quadratic Formula.
x=- b±sqrt(b^2-4ac)/2a
x=- 1±sqrt(1^2-4( 1)( - 12))/2( 1)
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Solve for x and Simplify
x=- 1±sqrt(1-4(1)(- 12))/2(1)
x=- 1±sqrt(1-4(- 12))/2
x=- 1±sqrt(1+48)/2
x=- 1±sqrt(49)/2
x=- 1± 7/2
The solutions for this equation are x= - 1± 72. Let's separate them into the positive and negative cases.
x=- 1± 7/2
x_1=- 1+7/2 x_2=- 1-7/2
x_1=6/2 x_2=- 8/2
x_1=3 x_2=- 4

Using the Quadratic Formula, we found that the solutions of the given equation are x_1=3 and x_2=- 4.