Решите уравнения : х^2 - 9 = 0 121 - x^2 = 0 y^2 - 4 = 0 1,96 - y^2 = 0
X^2=a a>0 !x!=a x=+-a х^2 - 9 = 0 x^2=9 x=+-3 121 - x^2 = 0 x^2=121 x=+-11 y^2 - 4 = 0 y^2=4 y=+-2 1,96 - y^2 = 0 y^2=1.96 y=+-1.4