7x-14=5x+9 3x-12=5x-20 56x=42(x+2)用方程解答(五年级的)

1.7x-14=5x+9 3.56x=42(x+2)
7x-5x=14+9 56x=42x+84
2x=23 56x-42x=84
x=11.5 14x=84
x=6
2.3x-12=5x-20
3x-5x=12-20
-2x=-8
x=4
3.56x=42(x+2)

7x-14=5x+9
7x-5x=9+14
2x=23
x=11.5
3x-12=5x-20
3x-5x=-20+12
-2x=-8
x=4
56x=42(x+2)
56x=42x+84
56x-42x=84
14x=84
x=6
LZ我也5年级……

7x-14=5x+9
7x-5x=9+14
2x=23
x=11.5
3x-12=-20
3x-5x=-20 +12
-2x=-8
x=4
56x=42(x+2)
56x=42x+84
56x-42x=84
14x=84
x=6

不会

7x-14=5x+9 7x-5x=9+14 2x=23 x=11.5
3x-12=5x-20 5x-3x=20-12 2x=8 x=4
56x=42(x+2) 56x=42x+42*2 56x-42x=84 14x=84 x=6

用方程解答:
7x-14=5x+9
7x-5x=9+14
2x=23
x=11.5
3x-12=5x-20
5x-3x=20-12
2x=8
x=4
56x=42(x+2)
56x=42x+84
56x-42x=84
14x=84
x=6