Question

What is the value of y?

A. 10
B. 110
C. 85
D. 55

Answer 1

D. 55
Explanation: 3 angles of a triangle must equal 180 so use the formula 180=(angle 1) +(angle 2) +(angle 3)
180=(40)+(y)+(y+30)
Test every answer until you get 180=180
180=40+55+(55+30)
180=40+55+85
180=180
So the answer is 55

Answer 2

D. 55°

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

Geometry

• All angles in a triangle add up to 180°

Explanation:

Step 1: Set Up Equation

40° + (y + 30)° + y° = 180°

Step 2: Solve for y

1. Combine like terms: 2y° + 70° = 180°
2. Isolate y term: 2y° = 110°
3. Isolate y: y° = 55°