решите уравнение (5+x)(4-x)-(4+x)(3-x)=2-x

EZ:

(5+x)(4-x)-(4+x)(3-x)=2x 20-5x+4x-x^2+4x-12-3x+x^2=2x 8=2x x=4

20+4х-5х-х^2-(12-4х+3х-х^2)=х-2
20-Х-х^2-12+Х+х^2=Х-2
8=Х-2
Х=10