Answer:
C) 60°
Step-by-step explanation:
The sum of the acute angles in a right triangle is 90°, so we have ...
α + β = 90
(5x³ +20) +(2x³ +14) = 90
7x³ = 56 . . . . . . subtract 34, collect terms
x³ = 8 . . . . . . . . divide by 7
Using this value in the expression for α, we find its measure to be ...
α = 5·8 +20 = 60
α = 60°
