Bài 1:
a)Tính
-60:{[(12-3).2]+2}
b)Tìm x
-70-5.(x-3)=45
-10+2.x=4^5:4^3
Bài 1: a)Tính -60:{[(12-3).2]+2} b)Tìm x -70-5.(x-3)=45 -10+2.x=4^5:4^3
By Maya
By Maya
Bài 1:
a)Tính
-60:{[(12-3).2]+2}
b)Tìm x
-70-5.(x-3)=45
-10+2.x=4^5:4^3
Bài 1:
a) `-60:{[(12-3).2]+2}`
`=-60:{[9.2]+2}`
`=-60:{18+2}`
`=-60:20=-3`
b) $-70-5.(x-3)=45$
$↔5.(x-3)=-115$
$↔x-3=-23$
$↔x=-23+3=-20$
c) $-10+2x=4^5:4^3$
$↔-10+2x=4^2=16$
$↔2x=26$
$↔x=13$
Bài `1` :
`a)`
`-60 :{[(12 – 3).2]+2}`
`= -60 :{[9.2] + 2}`
`= -60 :{18 + 2}`
`= -60 : 20`
`= -3`
`b)`
`-70 – 5.(x – 3) = 45`
`5.(x – 3) = -70 – 45`
`5.(x -3) = -115`
`x – 3 = -115 : 5`
`x – 3 = – 31`
`x = -31 + 3`
`x =28`
` – – — – – – — `
`-10 + 2.x = 4^5 : 4^3`
`-10 + 2.x =4^2`
`-10 + 2.x = 16`
`2.x = 16 – (-10)`
`2x = 26`
`x = 26 : 2`
`x = 13`