Question

Amelie solves the following system of equations.

x+y=20
3x-3y+30
Which values of x and y satisfy this system of equations?
x = 0, y = 20
x = 5, y = 15
x = 10, y = 0
x = 15, y = 5

Answer 1

The answer is : X=15,Y=5

I took the test

Answer 2

Answer: x = 15, y = 5

Explanation:

The given system is
`x+y=20.........................(1)//3x-3y+30...............................(2)`

Multiplying 3 on both sides of equation (1), we get

`3x+3y=60.........................(3)`

Now, adding (2) and (3), we get

`6x=90\\\\\Rightarrow\ x=15`

Substitute the value of x in (1), we get

`15+y=20\\\\\Rightarrow\ y=20-15\\\\\Rightarrow\ y=5`

Hence, the of x and y satisfy this system of equations is x = 15, y = 5.