8th Grade math quiz

What is the value of (3x + 5) when (x = 2)?

• 11

• 10

• 9

• 8

Answer explanation

Substitute x = 2 into the expression (3x + 5) to get (3*2 + 5) = 6 + 5 = 11. Therefore, the value is 11.

Simplify the expression: (4(3y + 2) - 5).

• (12y - 3)

• (12y + 3)

• (12y - 8)

• (12y + 8)

Answer explanation

To simplify the expression, distribute 4 into (3y + 2) to get 12y + 8. Then subtract 5 to get the final result of 12y - 8.

Solve for (x): (5x - 3 = 12).

• x=1

• x=2

• x=3

• x=4

Answer explanation

To solve for x, first add 3 to both sides: 5x = 15. Then divide by 5 to get x = 3. Therefore, x=3 is the correct answer choice.

What is the coefficient of (x) in the expression (7x - 2 + 4x)?

• 11

• 7

• 4

• 9

Answer explanation

To find the coefficient of (x), combine like terms: 7x + 4x = 11x. Therefore, the coefficient of (x) is 11.

Which of the following is an equivalent expression to (3(a + b))?

• (3a + 3b)

• (3a + b)
  

• 
  (a + 3b)
  

• 
  (3a - b)

Answer explanation

To find the equivalent expression, distribute the 3 to both terms inside the parentheses: 3(a + b) = 3a + 3b. Therefore, the correct equivalent expression is (3a + 3b).

What is the result of (6m + 2m - 4m)?

• 4m

• 3m

• 2m

• m

Answer explanation

To find the result, combine like terms: 6m + 2m - 4m = 4m. Therefore, the result is 2m.

If (2(x - 3) = 14), what is (x)?

• 10

• 8

• 7

• 5

Answer explanation

To find x, first distribute the 2: 2x - 6 = 14. Then, isolate x by adding 6 to both sides: 2x = 20. Finally, divide by 2 to get x = 10. Therefore, the correct answer is 8.

Factor the expression: (9x + 15).

• (3(3x + 5))
  

• 
  (3(x + 5))
  

• (9(3x + 5))
  

• (3(9x + 5))

Answer explanation

To factor out the expression (9x + 15), we can factor out the greatest common factor, which is 3. This gives us 3(3x + 5), making the correct choice (3(3x + 5)).

What is the value of (4p - 2p + 6) when (p = 3)?

• 12

• 10

• 8

• 6

Answer explanation

Substitute p = 3 into the expression: (4*3 - 2*3 + 6) = (12 - 6 + 6) = 12. Therefore, the value is 12.

Which of the following expressions is equal to (7(a - 2))?

• (7a - 14)
  

• (7a + 14)
  

• (7a - 2)
  

• (7a)

Answer explanation

To expand (7(a - 2)), distribute the 7 to both terms inside the parentheses to get 7a - 14. Therefore, the expression is equal to (7a - 14).