Question

The point (2,1) is a solution to which of the following systems of equations

Answer 1

D. x+y=3 and 3x-y=5

Explanation:

Answer 2

x+y = 3

3x-y = 5

Explanation:

x+y = 3

3x-y = 5

This system of equation will give the points(2,1).

Lets substitute the values x=2 and y = 1 in the equations:

x+y=3 equation 1

2+1 =3

3=3

3x-y=5 equation 2

3(2)-1=5

6-1=5

5=5

Lets solve the system:

Add the equations to eliminate y from the system:

x+y = 3

3x-y = 5

_______

4x = 8

Now divide both the sides by 4

4x/4 = 8/4

x=2

Now substitute the value of x in equation 1:

x+y=3

2+y=3

Combine the constants:

y=3-2

y=1....