4x-2x-7x= -5x
-5-3=-8
-5x-8
The best way to find the answer is to solve for x. To start you would add 38 and 39, getting 77, then subtract that from 180 to get the last angle in the triangle, 103. Finally, you would subtract 103 from 180, getting 77, to get x. The only thing you need to do now is to look at all of the answers and figure out which one makes sense for the answer you got. You know it can't be x<77 because it doesn't have the or equal to sign. You know it can't be x>103 because 77 is lower than 103. You know it can't be x<39 because 77 is greater than 39, so the answer has to be x > 38.
30% converted to a decimal is 0.30
310 x 0.3 = 93 students play an instrument
