Question

5)

D
-10 + 7x
70°
E
12x + 10
А с
A) 12
C) 8
B) 10
D) 2

Answer 1

B) 10

Explanation:

Exterior angle property: Exterior angle equals the sum of opposite interior angles.

12x + 10 = -10 + 7x + 70 {Subtract 10 from both sides}

12x = -10 + 7x + 70 - 10

12x = -10 + 70 - 10 + 7x {Combine like terms}

12x = 50 + 7x {Subtract 7x from both sides}

12x - 7x = 50

5x = 50 {Divide both sides by 5}

x = 50/5

x = 10