1) (24:3+45:5)+143=4.j+124
(8+9)+143=4j+124
160=4j+124
160-24=4j
4j=136
j=34
2)12×2:k=4
24/k=4
4k=24
k=6
3)(4×l+5)-6×2=5
4i+5=5+12
4i=17-5
4i=12
i=3
4)m:7+(123×3-53×4)=164
m:7+(123×3-53×4)=164
m:7+(369-212)=164
m:7=164-157
m:7=7
m=49
5)(n-45:9)×3=2185-2164
(n-6)×3=21
n-6=21:3
n=7+6
n=13
6)(24-7×3)×5÷3:0=30:10
(24-21)×5÷3:0=3
15÷3:0=3
5:0=3
0≠3
7)(p-28:7+200)×5=32000+3×10
(p-4+200)×5=32000+30
p-4+200=32030:5
p-4+200=6406
p=6406-200+4
p=6210
8)923-p+145=693
923-693+145=p
p=375
9)r×r+648=7×100×2×10+3×3
r×r+648=14000+9
r×r=14009-648
r×r=13361
