Finding Zeros of Quadratic Expressions

The video tutorial explains how to find the zeros of the quadratic expression x^2 - 7x - 18. It begins by setting the expression equal to zero and then factors it to find two numbers that multiply to 8 and add to -7. The factors identified are -9 and 2. By setting each factor equal to zero, the solutions x = 9 and x = -2 are obtained, which are the zeros of the expression.

What is the first step in finding the zeros of the quadratic expression x^2 - 7x - 18?

• Divide the expression by x

• Add 7 to both sides

• Multiply the expression by 2

• Set the expression equal to zero

Which two numbers multiply to 8 and add to -7 in the process of factoring the expression?

• -9 and 2

• -8 and 1

• 3 and 5

• 4 and -2

What is the result of setting the factor x - 9 equal to zero?

• x = 9

• x = -9

• x = 0

• x = 18

What is the result of setting the factor x + 2 equal to zero?

• x = -2

• x = -4

• x = 0

• x = 2

What are the zeros of the quadratic expression x^2 - 7x - 18?

• 9 and -2

• 6 and -4

• 7 and -1

• 8 and -3