Answer:
Y=2.37
Step-by-step explanation;
Make the top equation solve for x, x=3-y
subsitute (x=3-y) into 7x-y=-3
Get 7(3-y)-y=-3
use the distributive property and get 21-7y-y=-3
Combine like terms 21-8y=-3
Subtract 21 on both sides, -8y=-19
Divide by -8 on both sides
y=2.37