Answer:
∠A is equal to 73°
Explanation:
Because the two lines that move roughly bottom/left to top/right are marked as being parallel, we can say that ∠A + ∠B = 180°
With that we can take the two equations at the top, and add them together for a sum of 180°:
6x - 35° + 3x + 53° = 180°
9x + 18° = 180°
x + 2° = 20°
x = 18°
Now that we have x, we can solve for ∠A:
∠A = 6x - 35°
∠A = 6(18°) - 35°
∠A = 108° - 35°
∠A = 73°
We can test our answer by solving for ∠B. We know that ∠A and ∠B add up to 180°, so ∠B = 180° - ∠A = (180 - 73)° = 107°. Now let's solve for be given x and the original equation, and see if we have the right numbers:
∠B = 3x + 53°
∠B = 3(18°) + 53°
∠B = 54° + 53°
∠B = 107°
Which matches up, showing us that we have the correct answer.