Question

Solve the system by the method of substitution. 2x − y + 6 = 0 4x + y − 9 = 0

Answer 1

x=1/2

y=7

Explanation:

2x − y + 6 = 0

4x + y − 9 = 0

y = 9-4x

2x - (9-4x) +6 = 0

2x -9 +4x +6 =0

6x -3 =0

6x =3

6x/6 = 3/6

x =1/2

y = 9-4x

y = 9 -4(1/2)

y = 9 - 2

y =7

Answer 2

x=1/2

y=7

Explanation:

2x − y + 6 = 0

4x + y − 9 = 0

Solve the second equation for y

y = 9-4x

Substitute this into the first equation

2x - (9-4x) +6 = 0

Distribute the minus sign

2x -9 +4x +6 =0

6x -3 =0

Add 3 to each side

6x =3

Divide by 6

6x/6 = 3/6

x =1/2

Now find y

y = 9-4x

y = 9 -4(1/2)

y = 9 - 2

y =7