Question

What linear expression would you add to -4y+2 to have a dum of y?

Answer 1

`"The answer is:" \qquad \qquad \qquad \ L \ = \ 5 y - 2.`

Explanation:

`"Let the linear expression we need to add be:" \qquad L.`

`"So, from the question, we want" \ L \ "to achieve the following:"`

`\qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad L + ( -4 y + 2 ) \ = \ y.`

`\qquad :. \quad \ L + ( -4 y + 2 ) - ( -4 y + 2 ) \ = \ y - ( -4 y + 2 )`

`\quad :. \ \ L + color{red}cancel{ ( -4 y + 2 ) } - color{red}cancel{ ( -4 y + 2 ) } \ = \ y + 4 y - 2`

`\qquad :. \qquad \qquad \qquad \qquad \qquad \qquad \ L \ = \ 5 y - 2.`

`"This is our answer."`