Question

I need help with 18 I need an answer and a explanation

Answer 1

Mark's height last year was 46 inches.

Mark definitely grows over the past year. Let the height he grew be x.

Then, Mark's new height will be

`(46+x)\text{ inches}`

Let us represent Mark's height with M and Peter's height with P.

This means that

`M=46+x\text{ -----------(a)}`

and, from the question, Peter's height is

`P=51\text{ ----------(b)}`

The question says that Mark's height is 3 inches less than Peter's height. This we can write as

`M=P-3\text{ -------------(c)}`

Therefore, if we put Mark's and Peter's ages into equation c, we can find a value for x as follows:

`\begin{gathered} 46+x=51-3 \\ 46+x=48 \end{gathered}`

Since 46 + x = M, then Mark's height is 48 inches