Question

(х+3)(х-7)-(х-4)(х+4)=11

Answer 1

2 строчка (х+3)*(х-7)-х^2+16=11
(х+3)(х-7)-х^2=11-16
(х+3)(х-7)-х^2=-5
х^2-7х+3х-21-х^2=-5
х^2-4х-21-х^2=-5
-4х=-5+21
-4х=16
х=16/-4
х=-4