Question

Solve the system
{3x-y=4
-9x+3y=-12

Answer 1

Hello :
3x-y=4 .....(1)
-9x+3y=-12 ....(2)
by (1) : y = 3x-4
in (1) :   -9x +3(3x-4) = -12
-12=-12
infinity solution : ( x , 3x-4)    x in R