B1: Tính hợp lý:
`a. 37+(-17)-37+77`
`=(37-37)-(-17+77)`
`=0-60`
`=60`
`b. 11.107+11.18+11.25`
`=11.(107+18+25)`
`=11.150`
`=1650`
`c. 15.(-176)+15. 76+100-15`
`=-15.176+1140+100-15`
`=-1415`
`d. 17-(15-16) +16.(17-20)`
`=17-(-1)+16.(-3)`
`=18+(-48)`
`=-30`
B2:Tìm x:
`a.(2x-5)+17=6`
`(2x-5)=6-17`
`2x-5=-11`
`2x=(-11)+5`
`2x=-6`
`x=-3`
`b.5.(x-6)-2.(-x+3)=12`
`(5x-30)-(-2x+6)=12`
`x=48/7`
`c. 10.(x-7)-8.(x+5)=6.(-5)+24`
`(10x-70)-(8x+40)=-30+24`
`x=52`
`d. 24:(3x-2)=-3`
`\frac{24}{3x-2}=-3`
`x=-2`