решите уравнения:
x^2-70x=0
25-x^2=0

x^2 - 70x = 0 
x(x - 70) = 0
x_1 = 0     x_2 = 70

25 - x^2 = 0
x^2 - 25 = 0
(x-5)(x+5) = 0
x - 5  = 0    x + 5 = 0
x_1 = 5      x_2 = -5