5x+8y=25,6x-2y=30,解方程组

解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 解方程组 x-y/3-x+y/4=2 x-y/6-x+y/8=3 解方程组 {(x+y)/2+(x-y)/3=6 5(x+y)-2(x-y)=4 解方程组 X+Y/2+X-Y/3=6 4[X+Y]-5[X-Y]=2 解方程组:{二分之x+y+二分之x-y=6,4(x+y)-5(x-y)=2() 解二元一次方程组:{5(x+y)+3(x-y)=2{7(x+y)-3(x-y)=-6 解方程组：x+y/2+x-y/3=6 4(x+y)-5(x-y)=12 解方程组 25x-30y=15 5x-6y=3 解方程组｛5x+2y=6 ① 2x+5y=8 ② 解方程组6/x-7/y=40和2/x-5/y=8 8X+3Y+2=0 6X+5Y+7=0 解方程组 解方程组{3x+2y=8 5x-4y=6 加减消元法.