Question

Find the value of x.

Answer 1

`\boxed {\boxed {\sf A. \ 18}}`

Explanation:

The two angles are inside a right angle. The small box signifies a right angle/ 90° angle.

Therefore, the sum of the angle measures must equal 90. We can set up an equation.

`56+(x+16)=90`

Combine the like terms on the right side. The 2 constants: 56 and 16 can be added.

`(56+16)+x=90\\`

`72+x=90`

Since we are solving for x, we must isolate the variable. 72 and x are being added. The inverse of addition is subtraction, so subtract 72 from both sides.

`72-72+x=90-72`

`x=18`

x is equal to 18 and choice A is correct.