For most word problems, pick something to call X then replace phrases with "math" using X. I would use the first = X
Find the angle measures of a triangle if the second angle measures 10 degrees less than twice the first, and the third angle measures 25 degrees more than the second
Find the angle measures of a triangle if the second angle = 2X-10, and the third angle measures 25 degrees more than the second
Find the angle measures of a triangle if the second angle = 2X-10, and the third angle = 2X-10+25
Now you have the three angles:
X, 2X-10 and 2X-10+25