5x+n=3,8x+4+1,2 при n=-7

Question

5x+n=3,8x+4+1,2 при n=-7

Answer 1

5x-3,8x+n=4+1,21,2x+n=5,21,2x+(-7)=5,2
1,2x-7=5,2
1,2x=5,2+7
1,2x=12,2
x=12,2:1,2
x=10  0,2/10