=7(3x-y)？ - 10(3x-y)
=7×(-5/4+ 1/4)? - 10×(-5/4+ 1/4)
=7×(- 1)? - 10×(- 1)
=7+ 10
= 17
A -2B
=(x？ +x？ -x+ 1)-2(-x？ -x？ +x+ 1)
=x？ +x？ -x+ 1+2x？ +2x？ -2x-2
=3x？ +3x？ -3x- 1
=3×(-2)? +3×(-2)? -3×(-2)- 1
=-24+ 12+6- 1
=-7
There is no reward for this kind of problem next time.