Question

2x + y = 9
x = y - 3

Answer 1

x=2 and y=5

Explanation:

Steps:

I will solve your system by substitution.

x=y−3;2x+y=9

Step: Solve x = y − 3 for x:

Step: Substitute y − 3 for x in 2x + y = 9:

2x+y=9

2(y−3)+y=9

3y−6=9(Simplify both sides of the equation)

3y−6+6=9+6(Add 6 to both sides)

3y=15

3y/3=15/3 (Divide both sides by 3)

y=5

Step: Substitute 5 for y in x = y − 3 :

x=y−3

x=5−3

x=2(Simplify both sides of the equation)

Answer:

x=2 and y=5

Answer 2

x = 2 y = 5

Explanation:

Since we know that

x = y - 3

We can insert that into the equation above:

2(y-3) + y = 9

After having this equation, we can start by multiplying the numbers/variables in the parenthesis by 2.

2y - 6 + y = 9

Then add the common multiples (2y and y)

That makes:

3y - 6 = 9

We need to get 3y on a side by itself, so to do this, we can add 6 to (-6) and (9)

That makes:

3y = 15

Divide the 3 by 3 and 15 to get the y on its own:

y = 5

Now we need to find x, and to do this we can insert y into the equation:

2x + 5 = 9

Now subtract the 5 from the (5) and (9) and you'll get

2x = 4

Then you divide the 2 on both sides and get

x = 2

You can check your work by inserting x and y into the equation

2(2) + 4 = 9

Sorry for this super long explanation, and hope this helps