SOLUTION: How do you solve these? 2x^2-12x = -14 and -4r^2+21r = r + 13

Question 183988This question is from textbook Mcdougal Littell Algebra 2
: How do you solve these?
2x^2-12x = -14 and -4r^2+21r = r + 13 This question is from textbook Mcdougal Littell Algebra 2

Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
I'll do the first one to get you started

# 1

Start with the given equation.

Add 14 to both sides.

Notice we have a quadratic equation in the form of where , , and

Let's use the quadratic formula to solve for x

Start with the quadratic formula

Plug in , , and

Negate to get .

Square to get .

Multiply to get

Subtract from to get

Multiply and to get .

Simplify the square root (note: If you need help with simplifying square roots, check out this solver)

Break up the fraction.

Reduce.

or Break up the expression.

So the solutions are or

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