`1b)1/2 . \sqrt{1,69} . \sqrt{25/16}+1/4`
`=1/2 . 13/10 . 5/4 +1/4`
`=13/16+1/4`
`=17/16`
`2a)(x-2)/3=(-3)/4`
`⇔4(x-2)=(-3).3`
`⇔4x-8=-9`
`⇔4x=-9+8`
`⇔4x=-1`
`⇔x=-1/4`
Vậy `x=-1/4`
`b)2^x + 2^(x+3)=144`
`⇔2^x+2^x . 2^3=144`
`⇔2^x(1+2^3)=144`
`⇔2^x (1+8)=144`
`⇔2^x .9=144`
`⇔2^x=144:9`
`⇔2^x=16`
`⇔2^x=2^4`
`⇔x=4`
Vậy `x=4`