Answer:
x = 12
Step-by-step explanation:
We know that the total angle measure of a triangle is 180 degrees, so the sum of all the angles should be 180 degrees.
Therefore, we can add all the angles, set them equal to 180 and solve for x
2x+5 + 6x-5 + 7x = 180
We can combine all the x terms and all the numerical terms on the left side of the equation to get:
(2x+6x+7x) + (5-5) = 180
15x = 180
Then we can divide both sides by 15 to isiolate x
15x = 180
x = 180/15 = 12