Question

Solve the following correct to 2 decimal places.`(2m-1)(3-2)=0`?

Answer 1

Using first principles. The shortcut approach is just remembering the consequences of the first principle approach.

`m=1/2 = 0.50` to 2 decimal places

Explanation:

`(2m-1)(3-2)=0` is the same as `(2m-1)xx1=0`

1 times anything does not change its value giving:

`color(green)(2m-1=0)`

Add `color(red)(1)` to both sides. Moves the -1 from left to right of the = but in doing so changes it sign (shortcut approach)

`color(green)(2m-1=0 color(white)("dddd")->color(white)("dddd")2mcolor(white)("d") ubrace(-1color(red)(+1))=0color(red)(+1))`

`color(green)(color(white)("ddddddddddddd")->color(white)("dddd") 2mcolor(white)("d")+0color(white)("d")=color(white)("dd")1)`

To 'get rid' of the 2 from `2m` divide both sides by `color(red)(2)`

`color(green)(2m=1color(white)("ddddddd")->color(white)("dddd")2/color(red)(2) m=1/color(red)(2))`

But `2/2` is the same value as 1 and 1 times anything does not change its value. So `1xxm=m`

`color(green)(color(white)("dddddddddddddd")->color(white)("ddddd")m=1/2)`