Question

(2x + 5)² - 16 = 25 - (x - 4)²

Answer 1

(2x + 5)² - 16 = 25 - (x - 4)²   /-25-(x-4)²

(2x+5)²+(x-4)²-25-16=0

5x²+12x-25-16+41=0

5x²+12x-16+16=0

5x²+12x=0

x*5x+12=0

5x+12=0  /-12

5x= -12  / :5

x= -12/5

x∈{- 12/5,0}