解方程5X+18=3X+44 15X-1.4*5=5X+(107-2.2) 今天晚上就要,

解方程5X+18=3X+44 15X-1.4*5=5X+(107-2.2) 今天晚上就要,


5X+18=3X+44
2x=26
x=13
15X-1.4*5=5X+(107-2.2)
10x=107-2.2+7
10x=111.8
x=11.18



5x-(20-x)×2=86+4x


5x-(20-x)×2=86+4x
5x-(40-2x)=86+4x
5x-40+2x=86+4x
7x-4x=86+40
3x=126
x=42