Solve the equation

Question

20 x 2 = 5 x blank x 2

Answer 1

20x2 = 40 = 5x + ___ + x^2

x^2 + 5x + c = 40

x^2 +5x = 40-c

x^2 + 5x + (5/2)^2 = 40-c + (5/2)^2

(x +5/2)^2 = 40+25/4 -c= the missing term

x+5/2 = sqr(185/4 -c)

x = -5/2 +/-sqr(185/4 -c)

c = 40-x^2 -5x