Question

(1)若x-y=2,则_____=4 (2)若2x-6y=8,则_____=4 下面

由等式3x+3.14c=3y+3,14c能否得到x=y说明理由
已知x-3=1/3,14,求x^-3x+2
已知关于x的方程，3x+2a=x+7，小刚解时，把+7抄-7，得x=3，求原方程解

Answer 1

若x-y=2,则_2x-2y_=4 (2)若2x-6y=8,则__x-3y__=4

3x+3.14c=3y+3.14c 消去3.14c =>3x=3y =>x=y

x=3+(1/3)=10/3 => x^2=100/9 ; -3x=-10,
=>x^2-3x+2=100/9-10+2=100/9 -8=100/9 - 72/9 =28/9

3x+2a=x-7此时x=3=>3*3+2a=3-7 =>9+2a=-4=>13=2a=>a=6.5
=>3x+13=x+7 =>2x=-6 =>x=-3...ans