x-7=6,3x+4=13,5x-2×8=19怎求的啦
问题描述:
x-7=6,3x+4=13,5x-2×8=19怎求的啦
答
x-7=6
x=6+7
x=13
3x+4=13
3x=13-4
3x=9
x=9/3
x=3
5x-2×8=19
5x-16=19
5x=19+16
5x=35
x=35/5
x=7