Question

(х+3)(х-7)-(х-4)(х+4)=11

Answer 1

x²-7x+3x-21-(x²+4x-4x-16)=11

x²-7x+3x-21-x²-4x+4x+16=11

-4x+16-11=0

-4x=-16+11

-4x=-5

x=1.25

 

Answer 2

x2+3x-7x-21-(x2-16)=11

x2-4x-21-x2+16=11

-4x=16

x=-4

все просто xD