Algeb problem need help please thanks?

Question

18. If and form a system of equations, what is the value of ?

show the solution

Answer 1

x - y = 2

x + y = 4

Solve for x in the first equation:  x = 2 + y

Substitute into the second equation: (2 + y) + y = 4

Solve for y: 2 + 2y = 4  =>  2y = 2  =>  y = 1

Substitute back into the first equation: x - 1 = 2  =>  x = 3

Now place x & y values into third equation and solve:

3x + 2y = 3(3) + 2(1) = 11

Answer 2

x-y = 2 ------ eqn 1

x + y = 4 ---- eqn 2

add 1 and 2, You will get

x = 3

eqn 2 - eqn 1, you will get

y= 1

3x + 2y = 11

Answer 3

add the two equations to obtain 2x =6 (to do this you write one eqn under the other)

this gives x=3 and go back to either eqn to find y=1.

thus 3x+ 2y is 11

Answer 4

x - y = 2 => Eq. 1

x + y = 4 ==> Eq. 2

Add Eq. 1 and Eq. 2

2x = 6

x = 3

Substitute the value of x into Eq. 1 to find y

3 - y = 2

- y = 2 - 3

-y = -1

y = 1

x = 3

y = 1

3x + 2y =

3(3) + 2(1) = 9 + 2 = 11

Answer 5

Values of y:

x - y = 2

y = x - 2

x + y = 4

y = 4 - x

Value of x:

x - 2 = 4 - x

2x = 6

x = 3

Value of y:

= 3 - 2

= 1

Answer: x = 3, y = 1

Proof (1st equation):

3 - 1 = 2

Proof (2nd equation):

3 + 1 = 4

Value of 3x + 2y:

= 3(3) + 2(1)

= 9 + 2

= 11

Answer: 11 = 3x + 2y