Is this a function or not

No

Step-by-step explanation:

x=5 produces y=3 and y=5 so the relation is not a function.

y=-2x+7

Step-by-step explanation:

Hi there!

The form of slope-intercept form is given as y=mx+b, where m is the slope and b is the y intercept

We are given the slope (-2) and a point (3,1)

We can immediately substitute -2 as the slope in the equation

y=-2x+b

Now we need to find b

Because the line will pass through the point (3,1), we can use it to solve for b

Substitute 3 as x and 1 as y

1=-2(3)+b

multiply

1=-6+b

add 6 to both sides to isolate b

7=b

Substitute 7 as b into the equation

The line is y=-2x+7

Hope this helps!