Select each value of a for which you can solve the system by elimination without multiplying first. (There may be more than one)
ax+3y=7
4x+5y=15
a) -7
b) 3
c) -5
d) 4
e) -4
f) 5
g) -3
h) 7

HALP PLEASE!!!

Select each value of a for which you can solve the system by elimination without multiplying first.

ax+3y=7
4x+5y=15