Which equation can be solved by using inverse operations?

A. 2x² = x
Incorrect. Contains the linear term x.

B. 2x² = 6
Correct! Only contains a square term and constant.

C. 2x² = 6x − 2
Incorrect. Contains the linear term 6x.

D. 2x² − 3x = 9
Incorrect. Contains the linear term -3x.

Solve the equation below by using inverse operations.

4x² − 80 = 0

A. -4.472, 4.472
Correct! The square root of 20 is plus or minus 4.472.

B. -8.944, 8.944
Incorrect. Isolate x^2 before finding the square root.

C. -10, 10
Incorrect. Find the square root of 20.

D. -20, 20
Incorrect. Find the square root of 20.

Which equation can NOT be solved by using inverse operations?

A. 150 − 10x² = 75
Incorrect. There is no linear term.

B. 10x² = 150 − 75
Incorrect. There is no linear term.

C. 10x² − 75 = 0
Incorrect. There is no linear term.

D. 10x² = 75x
Correct! Contains the linear term 75x.

Determine which quadratic equation has solutions -3 and 9.

A. 2x² + 12x = 54
Incorrect. Simplify and then solve; the solutions to this equation are 3 and -9.

B. 3x² + 12x = -81
Incorrect. Simplify and then solve; the solutions to this equation are -3 and -9.

C. 2x² − 12x = 50
Correct!

D. 2x² + 12x = 50
Incorrect. Simplify and then solve; the solutions to this equation are 3 and -9.

Solve the following quadratic equation.

3x² + 6x = 25

A. ±5
Incorrect. Factor out the 3, complete the square and then solve.

B. -3.887, 1.887
Correct!

C. ±4
Incorrect. Factor out the 3, complete the square and then solve.

D. -6.881, 4.881
Incorrect. Factor out the 3, complete the square and then solve.