Question

x+y=55 x+2y=85, calcule o valor de 3y-2x ???

Answer 1

x+y=55 x(-2) -2x-2y=-110
x+2y=85 x+2y=85
25+2y=85 -x=-25
2y=60 x=25
y=30

3y-2x=
3.30-2.25=
90-50=40