Question

for elimination method the 1st question is Solve the system of equations −6x−5y=−12 and −8x−5y=4 by combining the equations.

Answer 1

eliminate y's
times first equation by -1 and add to 2nd

6x+5y=12
-8x-5y=4 +
-2x+0y=16

-2x=16
divide both sides by -2
x=-8
sub back

6x+5y=12
6(-8)+5y=12
-48+5y=12
add 48 to oth sides
5y=60
divide both sides by 5
y=12


x=-8
y=12
(-8,12)