Answer:
y = 38°
because QS is perpendicular to RP, which means that ∠SQP = ∠RQS
y = 4x + 6
-5x - 4x - 6 = 21
-9x - 6 = 21
-9x = 27
x = -3
y - 4(-3) = 6
y + 12 = 6
y = -6
(-3, -6)
