7х^2-3х(6-2х)=7х^2-18х+6х^2=13х^2-18х
6y=139-19
6y=120
y=120:6
y=20
BC=у-7,35
CD=у+51,2
ABCD=у+у-7,35+у+51,2=3у+43,85
AB: y=(-2/3)x+4
CD: y=-4
EF: x=5
А) /-1/2/=/-50/100/=50/100
/3/4/=/75/100/=75/100 - ответ
/9/20/=/45/100/=45/100
/-2/25/=/-8/100/=8/100