Solve Quadratics

What should you do first in solving this equation?
x² + 6x - 13 = 3

• Get factored form
• Find two numbers which add to make 6 and multiply to make -13
• Make it equal 0 by subtracting 3 on each side
• Type it all in a calculator.

Solve by factoring: x² + 3x - 18 = 0

• x = -3 and x = 6
• x = 3 and x = -6
• x = -9 and x = 2
• x = 9 and x = -2

Solve by factoring:  2x²+ 7x + 6 = 0

• x= 3/2 and x = 2
• x = -3/2 and x = -2
• x = 6 and x = 7
• x = -6 and x = -7

What is the first step to solving THIS equation by completing the square?
a² + 10a + 21 = 0

• Set the equation equal to zero
• Divide 10 by 2 and add the result to both sides
• Add a² and 10a together
• Subtract the 21

Complete the square for
x² + 12x + ____

• x² + 12x + 144
• x² + 12x + 36
• x² + 12x - 36
• x² + +12x - 144