Answer:
No single Correct answer. Both b and d will work
Step-by-step explanation:
You want to get rid of y.
The first equation has a 3 in front of the y
Therefore you would have to multiply the second equation by 3 or - 3
If you use -3 you would add the two equations
If you use 3 you would subtract the two equations.
It is either b or d. Both will give you the same answer.
- Three
 x + 3y =  10
-6x - 3y = - 15 Â Â Â Â Â Â Â Add
-5x = - 5 Â Â Â Â Â Â Â Â Â Â Â Divide by - 5
x = -5/-5
x = 1
+ Three
x  + 3y =  10
6x + 3y = 15 Â Â Â Â Â Â Â Â Â Subtract
-5x = - 5
x = -5/-5
x = 1 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Same thing.