Question

The relationship between $y$ and $x$ is graphically represented below.

Choose the correct equation for the relation shown in the figure.

• A. $y=30+x$
• B. $y=30x$
• C. $y=20-x$
• D. $y=30-x$

Answer 1

The correct option is D $y=30-x$

$\begin{array}{cccccc}x& 0& 5& 10& 15& 20\\ y& 30& 25& 20& 15& 10\\ & (30=30-0)& (25=30-5)& (20=30-10)& (15=30-15)& (10-30-20)\end{array}$
For the graph showing the relationship between $y$ and $x$. Each value of $y$ is obtained by subtracting the corresponding $x$ from 30.
Hence the equation for the relation shown in the graph is $y=30-x$.
Option C is correct.