Question

Y=-2.739x+222.15 how do I solve i don't understand it... it's also a graph question.

Answer 1

We know that the production of the years 1987 until 2017 is represented by the equation:

`y=-2.739x+222.15`

where x is the number of years that passed since 1987. (This means that x=0 gives the production of the year 1987, x=1 gives the production of year 1988 and so on.).

We would like to know tha change in the production of the period from 1992 to 2017.

To know the production in the year 1992 we have to plug the value x=5 in the equation of the production. Then:

`\begin{gathered} y=-2.739(5)+225.15 \\ =211.455 \end{gathered}`

To know the production in the year 2017 we have tu plug the value x=30 in the equation, then:

`\begin{gathered} y=-2.739(30)+225.15 \\ =142.98 \end{gathered}`

Now that we know the value of the production in each year we can use the rule of three to know what percentage of 211.455