The answer is C: (3,3)
x+3y=12;−4x+3y=−3Step: Solvex+3y=12for x:x+3y+−3y=12+−3y(Add -3y to both sides)x=−3y+12Step: Substitute−3y+12forxin−4x+3y=−3:−4x+3y=−3−4(−3y+12)+3y=−315y−48=−3(Simplify both sides of the equation)15y−48+48=−3+48(Add 48 to both sides)15y=4515y15=4515(Divide both sides by 15)y=3Step: Substitute3foryinx=−3y+12:x=−3y+12x=(−3)(3)+12x=3(Simplify both sides of the equation)Hope this helps!