a) 112 + (−12)+ (− 487)+ 512
b) 24 - 4^2 : 4.2 + 3
c) 21− 21.[(2.9 + 64 : 32)− 52 ]
2 câu trả lời
`a) 112 + (−12)+ (− 487)+ 512 `
`=112-12+512-487`
`=100+25`
`=125`
`b) 24 - 4^2 : 4.2 + 3`
`=24-16:8+3`
`=24-2+3`
`=22+3`
`=25`
`c) 21− 21.[(2.9 + 64 : 32)− 52 ]`
`=21− 21.[(18 + 2)− 52 ]`
`=21− 21.(20− 52)`
`=21− 21.(-32)`
`=21.[1-(-32)]`
`=21.(1+32)`
`=21.33`
`=693`