Question

help me

Answer 1

Thay x-y+1=7+1=8 vào pt

H=\(x^2.\left(x+1\right)-y^2.\left(y-1\right)+xy-3xy.\left(x-y+1\right)-95\)được

H=\(x^3+x^2-y^3+y^2+xy-3xy.8-95\)

H=\(\left(x^3-y^3\right)+\left(x^2+xy+y^2\right)-24xy-95\)

H=\(\left(x-y\right).\left(x^2+xy+y^2\right)+\left(x^2+xy+y^2\right)-24xy-95\)

H=\(\left(x^2+xy+y^2\right).\left(x-y+1\right)-24xy-95\)

H=\(\left(x^2 +xy+y^2\right).8-24xy-95\)

H=\(8.\left(x^2+xy+y^2-3xy\right)-95\)

H=\(8.\left(x^2-2xy+y^2\right)-95\)

H=\(8.\left(x-y\right)^2-95\)

H=\(8.7^2-95\)=297

Vậy H=297

Answer 2

297