SOLUTION: Solve the simultaneous equation 3x+5y=21 3x-y=3

Question 808069: Solve the simultaneous equation
3x+5y=21
3x-y=3
Answer by MathTutor16(2) (Show Source): You can put this solution on YOUR website!
3x+5y=21 ...1
3x-y=3 ...2
The easiest way to solve this problem would be to get rid of one of the variables. In both equations you have 3x. If you subtract the two equations, you get the following:
0x+6y=18
6y=18
From this, it follows that y=3. If you now substitute this value into EITHER equation, you will be able to find x. Plugging into the second equation:
3x-3=3
3x=6
x=2
Therefore, the answer is x=2,y=3. To check, you can plug in these values into either equation:
3x+5y=21
(3*2)+(5*3)=21
6+15=21
21=21
This proves that our answer is correct.
RELATED QUESTIONS
Solve the following simultaneous equation using cramer's rule: 3x-2y=3;... (answered by ikleyn)

by eliminating solve the pairs of simultaneous equation 6x-5y=-7 3x+4y=16 (answered by josgarithmetic,MathTherapy)

4x+5y=39 and 3x-18y=9 solve the simultaneous equation by using substitution method (answered by josgarithmetic)

Solve the simultaneous equations. 3x+4y=-3,... (answered by josgarithmetic)

Solve the simultaneous equation graphically. x+y=5 3x+y=9... (answered by Alan3354)

by using row reduction solve the following simultaneous equation. 2x-y=5 3x+4y=13 (answered by checkley77)

Solve graphically the simultaneous equation.3x+2y=9 Y- 2x=1 (answered by htmentor)

solve the following simultaneous equation by using cramer's rule 3x+2y=13... (answered by Edwin McCravy)

Solve the simultaneous equation 2x-3y=17 and... (answered by ikleyn,Boreal)