Expressions Unit Test Review

Which of the following expressions is a trinomial?

• 2a + 5(4x)

• 3(4x) x 7

• 5(2x + 1)

• 9-3(5x)+13a

Answer explanation

Remember a trinomial has 3 terms. A term is a collection of variables and numbers (like 3x) put together using multiplication or dividion. We separate term using additiion and subtraction.

• 108

• -108

• 36

• -18

Answer explanation

Remember to use order of opearaitons on this

P: (4 - 7) = -3

E (-3)² = 9

(remember a - times a - is a positive)

M: 3(9) = 27

A: 9 + 27 = 36

Tags

CCSS.6.EE.A.2C

If the expression 3x² + 1 is evaluated for x = -4, which of the following would be the result?

• -47

• 48

• 49

• 50

Answer explanation

This is tricky because you are substituting a negative number in for a base to an exponent. Remember if you are putting this in your calculator use ( ). Here is what is should look like and why....

3(-4)² + 1

This should give you 16 (NOT -16) because -4 x -4 = 16.

3(16) + 1 = 49

Tags

CCSS.6.EE.A.2C

The expression 5(6x + 9) - (8x + 5) can be rewritten as which of the following?

• -10x + 20

• 22x + 40

• -10x + 70

• 22x + 50

Answer explanation

This is ticky becuase we are subtracting the two expressions so pease change to add the negative to help keep track of signs.

LOOK: Rewrite:

5(6x + 9) + -1(8x + 5)

30x + 45 + -8x + -5

22x + 40

Tags

CCSS.6.EE.A.3

What is the greatest common factor of 120 and 84?

• 12

• 18

• 3

• 6

Which of the following calculations is incorrect if you need to decrease 38 by 7%

• 38(1 - 0.7)

• 38 - 0.7(38)

• (38 - 7) x 9.3

• 38(.93)

Answer explanation

Percent decrease can be represented by:

Taking 0.07 (38) then subtracting by 38. Looks like:

38 - 38(0.07)

Factor out:

38 (1 - 0.07)

Which is 38(0.93)

Tags

CCSS.6.RP.A.3C

Which of the following is Not a factor of the expression 6x + 30?

• 3

• 5x

• 5

• 6

Tags

CCSS.7.EE.A.1

Which choice is a term in the expression 4x² + 7x + 3

• x² + 7

• 4x² + 7

• x²

• 4x²

Answer explanation

A term - a collection of variables and numbers (including expoents) that are together by multiplication and division.

Ex: 3 5xy 2x²

Tags

CCSS.6.EE.A.2B

What will the coefficients of each term be after simplifying the expression show below?

2y + 8x + 7z - 6y - 2z + 5x + 4y

• 13, 0, 5

• 8, -6, 12, 5

• 13, 12, 5

• 13, 0, 9

Answer explanation

When I simplify this down I get:

8x + 5x = 13x

2y + -6y + 4y = 0y

7z + -2z = 5z

So: 13, 0, 5

Tags

CCSS.7.EE.A.1

Which expression is not equivalent to 5x + 3 - (7x - 4)

• -2x - 1

• -2x + 3 + 4

• (5-7)x + 7

• -2x + 7

Answer explanation

Change subtraction to addition:

5x + 3 + -1(7x - 4)

5x +3 + -7x + 4

-2x + 7

Tags

CCSS.6.EE.A.4