a. `25``-`(`2`.`x`+`10`)=`5`
( `2` `x` `+` `10`) = `25` `-` `5`
`2` `x` + 10 = 20
`2` `x` = `20` `-` `10`
`2` `x` = `10`
`x` = `10` : `2`
`x` = `5`
b. `2`. `315` `-` (`135` `-` `x`)=`215`
`630` `-` ( `135` `-` `x` ) = `215`
( `135` `-` `x` ) = `630` - `215`
`135` `-` `x` = `415`
`x` = `135` - `415`
`x` = -280
c. 128+(202-x)=330
( 202 - x ) = 330 - 128
202 - x = 202
`x` = 202 - 202
`x` = 0
d. x-320:32=25.16
`x`- 10 = 400
`x` = 400 + 10
`x` = 410
e. (x-120).9=450
( `x` - 120) = 450 : 9
`x` - 120 = 50
`x` = 50 + 120
`x` = 170