Q:

Solve this system of equations by elimination:8x+9y=4812x+5y=21

Accepted Solution

A:
Answer:Let's solve your system of equations by elimination. 8x+9y=48;12x+5y=21 Steps: Multiply the first equation by 5,and multiply the second equation by -9. 5(8x+9y=48) −9(12x+5y=21) Becomes: 40x+45y=240 −108x−45y=−189 Add these equations to eliminate y: −68x=51 Then solve−68x=51for x: −68x /−68 = 51 /−68  (Divide both sides by -68) x=  −3 /4 Now that we've found x let's plug it back in to solve for y. Write down an original equation: 8x+9y=48 Substitute −3 /4 8x+9y=48: 8( −3 /4 )+9y=48 9y−6=48 (Simplify both sides of the equation) 9y−6+6=48+6 (Add 6 to both sides) 9y=54 9y /9  =  54 /9  (Divide both sides by 9)   y=6 Answer:  x=  −3 /4  and y=6Hope This Helps!  Have A Nice Day!!