优质解答
代入法6x+8y=400 ---- 1x+y=65 ---- 2代入法由方程2得x=65-y ---- 3将3代入1得6（65-y)+8y=400390-6y+8y=4002y=10y=5将y=5代入2得x+5=65x=60加减消元法6x+8y=400 ----- 1x+y=65 ----- 2由2方程两...
代入法6x+8y=400 ---- 1x+y=65 ---- 2代入法由方程2得x=65-y ---- 3将3代入1得6（65-y)+8y=400390-6y+8y=4002y=10y=5将y=5代入2得x+5=65x=60加减消元法6x+8y=400 ----- 1x+y=65 ----- 2由2方程两...