Answer:
(-12,6)
Explanation:
using elimination method multiply the second equation by -1
18x - 16y = -312
-78x + 16y = -408
add the two equations
60x = -720
divide by 60
x = -12
plug -12 into the first equation
18(-12) - 16y = -312
-216 - 16y = -312
-16y = -96
y = 6