Tìm x, biết: (9x^2 - 49) + (3x + 7) (7x + 3) = 0

Tìm x biết
e, ( 9x^2- 49)+ (3x + 7 ) ( 7x+3) = 0
g, ( x - 4)^2= ( 2x-1)^2
h, x^2- x^2+ x - 1 = 0
i, x + x^2+ x + 1 = 0
k, x(x+ 16) - 7x - 42 = 0
m, x^2+ 7x + 12 = 0
n, x^2- 7x + 12 = 0