Question

What will be the linear function of the following?

• A. $y=2x+x$
• B. $y=2x+1$

Answer 1

The correct option is B $y=2x+1$

For this graph we have two points ($-5,-9$) and ($7,15$).

Which means when $x=-5,y=-9$ and when $x=7,y=15$

For equation $y=2x+x$, putting the values:

$2x+x=2\times (-5)+(-5)=-10-5=-15$ which is not equal to $y$.
Similarly, for the other pair,
$2x+x=2\times 7+7=14+7=21$ which is also not equal to $y$.

Thus this equation does not hold good for this graph.

For the equation $y=2x+1$, putting the values:
$2x+1=2\times (-5)+1=-10+1=-9$, which is equal to the corresponding value of $y$.
Again, $2x+1=2\times 7+1=14+1=15$, which equals to $y$.

Therefore this equation satisfies this graph.

Option (b.) is correct.