Question

What is the value of x in the equation 3x – y = 18, when y = 27?

a.5
b.7
c.45
d.63

Answer 1

15

Explanation:

3x - y = 18

Insert the value of y in the equation.

3x - 27 = 18

Shift -27 to the other side of the equation.

3x = 18 + 27

3x = 45

x = 45 ÷ 3

x = 15

So please check if your options and the equation are correct.

Answer 2

x = 15

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Equality Properties

• Multiplication Property of Equality
• Division Property of Equality
• Addition Property of Equality
• Subtract Property of Equality

Explanation:

Step 1: Define

3x - y = 18

y = 27

Step 2: Solve for x

1. Substitute in y: 3x - 27 = 18
2. Isolate x term: 3x = 45
3. Isolate x: x = 15