Answer:
x = 19 degrees
y = 84 degrees
Explanation:
recall that for an isosceles triangle (which is pictured), the base angles have the same value.
In our case, we can see that the base angles are 48 deg and (3x-9) deg
if they are equal, we can equate them like this:
48 = 3x-9 (add 9 to each side)
48 + 9 = 3x
57 = 3x (divide both sides by 3)
x = 57/3
x = 19 degrees (answer)
also recall that the sum of the interior angles of a triangle add up to 180 deg, hence
48 deg + 48 deg + y deg = 180 deg
2(48) + y = 180
96 + y = 180
y = 180 - 96
y = 84 deg