Write the sum of the three angles and set this sum equal to 180. Use (degree measure) to denote the third, unknown, angle:
4x - 7 + 6x-4 + (degree measure) = 180
Now subtract 4x - 7 + 6x-4 from both sides. We get:
(degree measure) = 180 - (4x - 7 + 6x-4). Simplify this:
= 180 + 7 - 4x - 6x + 4, or
= 180 + 11 - 10x, or
(degree measure) = 191 - 10x (answer)
This represents the degree measure of the third angle in the triangle.