a: =>3/4:x=2/3-1/4=8/12-3/12=5/12
=>x=3/4:5/12=3/4x12/5=36/20=1,8
b: =>(-2)x-1=256
=>x-1=8
hay x=9
`1/4 + 3/4 : x = 2/3`
`3/4 : x = 2/3 - 1/4`
`3/4:x = 5/12`
`x=3/4 : 5/12`
`x=3/4 xx12/5`
`x=9/5`
____________________
\(\left(-2\right)^{x-1}+2007=2263\)
\(\left(-2\right)^{x-1}=2263-2007\)
\(\left(-2\right)^{x-1}\) `=256`
`=> (-2)^(x-1) = 2^8`
`=> x-1=8`
`x=8+1`
`x=9`
________________________
`|1/2 - x| + 1/3 = 2 1/4`
`|1/2 - x| + 1/3 =9/4`
`|1/2 - x| = 9/4 - 1/3`
`|1/2 - x| = 23/12`
`@TH1:`
`1/2-x=23/12`
`x=1/2-23/12`
`x= 6/12 - 23/12`
`x=-17/12`
`@TH2:`
`1/2-x=-23/12`
`x=1/2 - (-23/12)`
`x=1/2 + 23/12`
`x=6/12+23/12`
`x=29/12`
