Bài tập về nhà lớp 6

Đáp án:

Giải thích các bước giải:

 `88-3.(7+x)=64`

`3.(7+x) = 88 - 64`

`3.(7+x) = 24`

`7+x=24:3`

`7+x=8`

`x=8-7`

`x=1`

_______________________

`60-3.(x-2)=51`

`3.(x-2)=60-51`

`3.(x-2)=9`

`x-2=9:3`

`x-2=3`

`x=3+2`

`x=5`

________________________

`70-5.(2x+3)=45`

`5.(2x+3)=70-45`

`5.(2x+3)=25`

`2x+3 = 25:5`

`2x + 3 = 5`

`2x = 5-3`

`2x=2`

`=> x = 1`

______________________

`123 - 5.(x+4)=38`

`5.(x+4)=123-38`

`5.(x+4)=85`

`x+4=85:5`

`x+4=17`

`x=17-4`

`x=13`

___________________________

`125 . 5.(4+x)=15`

`5.(4 + x) = 125 - 15`

`5.(4+x) = 110`

`4+x = 110 : 5`

`4+x=22`

`x=22-4`

`x=18`

_______________________________

`2^6 + (5+x)=3^4`

`5+x = 3^4 - 2^6`

`5+x = 17`

`x=17-5`

`x=12`

________________________

`5x - 5^2 = 10`

`5x - 5^2 = 5^2`

`5x = 10 + 5^2`

`5x = 10 +25`

`5x = 35`

`x=35:5`

`x=7`

____________________

`9x - 2.3^2 = 3^4`

`9x - 18 = 81`

`9x=81 +18`

`9x = 99`

`x=99:9`

`x=11`

______________________________

`#LưuVy`