If the moving object is undergoing constant acceleration, then

(take the average of the initial and final velocities, if they're given)
If you don't know the acceleration or initial/final velocities, then you have to resort to the usual definition,

where
is the change in position and
is the duration of the interval.
First, you replace x with -3.
It will look like -3/3.
Then you divide and get -1.
Answer:
y=17
Step-by-step explanation:
4x+2y=70
x+y=26
2x+2y=52
2x=18
x=9
y=26-9
y=17