Tìm x: a, 3( x + 2 )^2 + ( 2x - 1 )^2 - 7( x + 3 )( x - 3 ) = 36; b, ( x + 3 )^2.( x^2 + 3x + 9 ) + x( x+ 2 )( 2 - x ) = 1; c, ( x + 1) ^3 - ( x - 1 )^3 - 6( x - 1 )^2 = -19

tìm x:
a, 3(x+2)^2+(2x-1)^2-7(x+3)(x-3)=36
b, (x+3)^2.(x^2+3x+9)+x(x+2)(2-x)=1
c, (x+1)^3-(x-1)^3-6(x-1)^2=-19
chi tiết pls