Q:

Solve the system using elimination. –10x – 3y = –18 –7x – 8y = 11

Accepted Solution

A:
ANSWERx=3, y=-4EXPLANATIONThe given system is :First equation:[tex] - 10x - 3y = - 18[/tex]Second equation:[tex] - 7x - 8y = 11[/tex]Let us multiply the first equation by 7 to get,Third equation;[tex] - 70x - 21y = - 126[/tex]Let us multiply the second equation too by 10 to get,Fourth equation:[tex] - 70x - 80y = 110[/tex]Subtract the fourth equation from the third equation:[tex] - 21y + 80y = - 126 - 110[/tex][tex] 59y = -236[/tex]Divide both sides by 59.[tex]y = - 4[/tex]Put y=-4 into the second equation and solve for x.[tex] - 7x - 8( - 4) = 11[/tex][tex] - 7x + 32 = 11[/tex][tex] - 7x = 11 - 32[/tex][tex] - 7x = - 21[/tex][tex]x = 3[/tex]The solution is x=3, y=-4