Simplify these expressions and find their values if `x=3, a-1 and b=-2`
(i) `3x-5-x+9`

Explanation

Given that,

`x=3, a=-1, b=-2`

(i) `3x-5-x+9`

`=(3x-x)-5+9`

`=2x+4`

`=2(x+2)`

`=2(3+2)`

`=2(5)`

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