Question

Which equation could you use to solve for the value of x?A.3× + 10 =180B.3x + 10 = 2xC.3x + 10 - 2x = 180D.3x + 10 + 2x = 180

Answer 1

The given diagram shows a line segment AC intercepted by segment D at point B.

This forms two angles ∠ABD and ∠CBD, both angles are a linear pair, which means that they are supplementary. So we know that:

`\angle\text{ABD}+\angle\text{CBD}=180º`

If ∠ABD=(3x+10)º and ∠CBD=(2x)º, then their sum is

`(3x+10)º+(2x)º=180º`

From this expression, you can determine the value of x.

The correct answer is D.