What is the value of x+y? 2x+3y=12, 2x-y=4

Question

Math, please help

Answer 1

2x+3y = 12

2x-y=4

 

You can just solve for x and y first. Subtract the second equation from the first to eliminate x: 

 

2x+3y = 12 

-(2x-y) = -4

 

0+4y = 8

 

y = 2 

 

You can use y=2 in either of the original equations to find x. Plugging in to the equation 2x-y=4 gives: 

 

2x-(2)=4 

2x=6

x=3

 

x=3   and   y=2   

 

x+y = 5 

Answer 2

It Looks like you have a system of equations, two equations, two unkowns(variables). They just threw in an extra step. First Solve for your two unknowns, then add them. So, to start.... It looks like the second equation will sole for Y quite easily, 2x-y=4 becomes, 2x-4=y. Substitute this into the first equation for y, and you get, 2x+3(2x-4)=12. Solving for x, 2x+6x-12=12, becomes 8x=24, gives x=3. substitute back into the first and y=2(3)-4, y=2. you can verify in either equation, 2(3)+3(2)=12. Correct. so finally, x+y=3+2=5.