pre algebra review (3 units)

A letter that represents a number is called a _____.

• variable

• coefficient

• constant

• term

Answer explanation

In mathematics, a letter that represents a number is called a variable. Variables are used to represent unknown values or quantities in equations and expressions. Coefficients, constants, and terms are related concepts, but they do not represent numbers in the same way as variables do.

Tags

CCSS.6.EE.A.2B

What is the constant in the following expression?
8y + 5 - 35p

• 8

• 35p

• 5

• 8y

Answer explanation

In the given expression, 8y + 5 - 35p, the constant is the term that does not have any variable associated with it. Among the options, '5' is the term without any variable, making it the constant in the expression.

Tags

CCSS.6.EE.A.2B

3(3x +1)

• 9x +3

• 3x + 3

• 12x

• 9x + 1

Answer explanation

To solve the question 3(3x + 1), we need to apply the distributive property by multiplying 3 with both terms inside the parentheses. So, 3 * 3x = 9x and 3 * 1 = 3. Combining these results, we get the correct answer: 9x + 3.

Tags

CCSS.6.EE.A.3

Which of these are like terms in the following expression:
3x + 7 - 9x + 24y + 2x²

• 7, 24y

• 3x, 9x

• 3x, -9x

• 3x, -9x, 2x²

Answer explanation

In the given expression, like terms are those that have the same variable and exponent. The terms 3x and -9x both have the variable x raised to the power of 1, making them like terms. The other options contain terms with different variables or exponents, so they are not like terms.

Tags

CCSS.6.EE.A.2B

Simplify the expression: 2x + 1 + 7x 

• 10x

• 10

• 9x + 1

• 9 + 1x

Answer explanation

To simplify the expression in the question, combine the like terms: 2x and 7x. Adding them together gives 9x. The constant term, 1, remains unchanged. So, the simplified expression is 9x + 1, which is the correct choice.

Tags

CCSS.7.EE.A.1

Simplify the following expression:
-6x + 4(-x - 3)

• -2x - 12

• 10x + 12

• -10x - 12

• -2x + 12

Answer explanation

To simplify the given expression, -6x + 4(-x - 3), first distribute the 4 to both terms inside the parentheses: -6x - 4x - 12. Then, combine the like terms: -6x - 4x = -10x. So, the simplified expression is -10x - 12, which is the correct choice.

Tags

CCSS.6.EE.A.3

Simplify by combining like terms:
5a + 2b - 3a + 4

• 8a + 2b + 4

• 2a + 2b + 4

• 8ab

• 4ab + 4

Answer explanation

To simplify the given question, we need to combine like terms. We have 5a and -3a, which combine to 2a. The other terms, 2b and 4, do not have any like terms to combine with. So, the simplified expression is 2a + 2b + 4, which is the correct choice.

Tags

CCSS.7.EE.A.1

Which of the following is equivalent to
-8+9(5 + 2x)?

• -5 - 2x

• 18x+37

• -37 + 18x

• 18x - 53

Answer explanation

To solve the question, first distribute the 9 to both terms inside the parentheses: 9(5) + 9(2x) = 45 + 18x. Then, combine the -8 with the 45: -8 + 45 = 37. Finally, rewrite the expression as 18x + 37, which is the correct choice.

Tags

CCSS.6.EE.A.3

Simplify the following expression:
-8 (5b + 2) -7 (b - 5)

• -33b + 19

• -47b² +  21

• 33b - 19

• -47b -19

Answer explanation

To simplify the given expression, distribute the -8 and -7 to the terms inside the parentheses: -8(5b) - 8(2) - 7(b) + 7(5). This results in -40b - 16 - 7b + 35. Combine like terms to get -47b + 19, which simplifies to -47b - 19, the correct choice.

Tags

CCSS.6.EE.A.3

3x²+4x²+7 is

• 7x⁴+7

• 7x² + 7

• 7x⁵

• 7

Answer explanation

The question asks to simplify the expression 3x^2 + 4x^2 + 7. To do this, combine the like terms, which are the terms with the same variable and exponent. In this case, 3x^2 and 4x^2 are like terms. Add them together to get 7x^2. The simplified expression is 7x^2 + 7, which is the correct choice.

Tags

CCSS.6.EE.A.4