Q:

-3x+3y=9 2x−7y=−14 ​

Accepted Solution

A:
Step: Solve

3
x
+
3
y
=
9
for x:

3
x
+
3
y
=
9

3
x
+
3
y
+

3
y
=
9
+

3
y
(Add -3y to both sides)

3
x
=

3
y
+
9

3
x

3
=

3
y
+
9

3
(Divide both sides by -3)
x
=
y

3

Step: Substitute
y

3
for
x
in
2
x

7
y
=

14
:
2
x

7
y
=

14
2
(
y

3
)

7
y
=

14

5
y

6
=

14
(Simplify both sides of the equation)

5
y

6
+
6
=

14
+
6
(Add 6 to both sides)

5
y
=

8

5
y

5
=

8

5
(Divide both sides by -5)
y
=
8
5

Step: Substitute
8
5
for
y
in
x
=
y

3
:
x
=
y

3
x
=
8
5

3
x
=

7
5
(Simplify both sides of the equation)

Answer:
X=-7/5 and y= 8/5