Answer:
Both angles B and C are equal to 40°
Explanation:
The diagram tells you that the triangle is an isosceles triangle. From this we know that angles B and C will be equal to each other. To find what the angle measures are, we are going to set the two given expressions equal to each other, solve for x, and the plug x back in to get the two angle measures.

Now we are going to plug x back into each expression to solve for angles B and C.
Angle B
⇒

Angle C
⇒

Both angles B and C are equal to 40°