CORRECT ANSWER 42 degrees = Angle A
explanation-
When solving for a triangle, regardless of shape, the angles will always have to add up to 180 degrees. We are given that the angle at the top (let's call it C) is 79 degrees. 180 minus 79 is 101. This means of the two angles left, we have 101 degrees that need to be filled between angle A and the unnamed angle. We are given the variable X in order to add among our angles to try and solve them. X+48 will give us angle A and X+65 will give us the unnamed angle. However, 65 and 48 added to 79 will give us more than 180, which means our X is less than 1.
The easiest way to solve for X is to start to subtract numbers by our given.
-2 + 48 is 46 and -2 + 65 is 63. 63 plus 48 is still more than 101. So this is incorrect.
Correct answer - X = -6. -6 + 48 is 42, and -6 + 65 is 59. 59+42 is 101. So our angle A is 42 degrees.
I hope this helps & good luck !