Which expression is equivalent to 5(x² − 4x) − (x + 1)?

A. 5x ² − 21x + 1
Incorrect. Check your signs when using the distributive property.

B. 5x ² − 5x - 1
Incorrect. Check your multiplication of integers for a sign error.

C. 5x ² − 21x − 1
Correct!

D. 5x ² − 5x + 1
Incorrect. Check your multiplication integers for a sign error.

Simplify the expression 6 − 3(5x + 2) − 10x.

A. - 25x
Correct! You are doing a great job!

B. 5x + 6
Incorrect. You probably made a sign.

C. 8 − 25x
Incorrect. You forgot to distribute -3 to both.

D. 12 − 25x
Incorrect. You probably made a sign.

Simplify the polynomial below.

-3x(7x − 4) + 6x − (13 − 24x²)

A. 3x² + 18x − 13
Correct! You are a math whiz!

B. -24x² − 15x − 17
Incorrect. You made an error when you were applying the distributive property.

C. -24x² + 10x − 17
Incorrect. You made a distribution and sign error.

D. 3x² + 18x + 13
Incorrect. You made a sign error.

Tammy drew a floor plan for her kitchen, as shown below.

Which expression represents the perimeter of Tammy's kitchen floor?

A. 10x + 6
Incorrect. You made an error when distributing.

B. 10x + 12
Correct! Keep on going!

C. x² + 13x + 5
Incorrect. You found the area instead of the perimeter.

D. 5x + 6
Incorrect. You forgot to include two sides of the rectangle when determining the perimeter.

Which expression is equivalent to 6x +2y?

A. 48x + 16y
Incorrect. This expression in simplified form is 16(4x + y).

B. 3(2x − 6) + 2(y − 9)
Incorrect. This expression in simplified form is 6x − 2y − 36 or 2(3x − y − 6). C. 3(2x + 6) + 2(y + 9)
Incorrect. This expression in simplified form is 6x − 2y + 36 or 2(3x – y + 6).

D. 3(2x − 6) + 2(y + 9)
Correct! You are doing a great job!