Find the value of x.

x = 20

Step-by-step explanation:

The angle is 90 degrees so we can make an equation

with it.

3x + 10 + x = 90

Combine like terms

4x + 10 = 90

subtract 10 from both sides to cancel it out

4x = 80

Now divide by 4 to leave x by itself

x = 20

Now you can check if it's correct by plugging in x to the equation given

3(20) + 10

60 + 10

70

20 + 70 = 90 degrees

D: 20 degrees

Step-by-step explanation:

First, we add 3x+10 and x together because they are within a right angle, which is 90 degrees. This gives the equation 4x+10=90. We solve from here.

We subtract 10 from both sides to isolate the x-variable. 90 minus 10 equals 80. This gives us the equation 4x=80. To further isolate the x-variable, we divide both sides by 4. 80 divided by 4 equals 20.

This leaves us with x=20.

Hope this helped!