DCAS Algebraic Reasoning

Question 1

If 3x + 5 = 20, what is the value of x?

Accepted Answer

5

Answer

Subtracting 5 from both sides gives 3x = 15, then dividing by 3 gives x = 5.

Question 2

Which expression represents '7 less than 4 times a number n'?

Accepted Answer

4n - 7

Answer

'4 times a number n' is 4n, and '7 less than' means subtract 7 from it, giving 4n - 7.

Question 3

What is the value of 3² + 4 × 2 - 6 ÷ 3?

Accepted Answer

15

Answer

Using order of operations: 3² = 9, then 4×2 = 8 and 6÷3 = 2, giving 9 + 8 - 2 = 15.

Question 4

If f(x) = 2x - 3, what is f(4)?

Accepted Answer

5

Answer

Substituting x = 4: f(4) = 2(4) - 3 = 8 - 3 = 5.

Question 5

Which inequality represents 'a number x is at least 12'?

Accepted Answer

x ≥ 12

Answer

'At least 12' means x can equal 12 or be greater, which is written as x ≥ 12.

DCAS - Delaware Comprehensive Assessment System Practice Test