Question

What is the solution to the system 3x+2y=-3 and 9x +4y=3

Answer 1

Answer:

x=3, y=-6

Step-by-step explanation:

As you know there are many ways to solve this question! First is Subsitutuion, Second is Elimination, and Third is Graphing!

Let’s begin with our detailed answer:

As you know subsitution is solving for a variable and then it can be used as a variable substitution to figure out x and y.

So in our system of equations:

$\left \ {3x+2y=-3}} \atop {9x+4y=3}} \right.$

I will just take one equation and solve for x but it actually dosent matter which variable you subsitutue and solve for.

$\left \ {3x+2y=-3}} \atop {9x+4y=3}} \right.$

To eliminate this question we can divide the top part by -3:

$\left \ {-9x-6y=9}} \atop {9x+4y=3}} \right.$

Let‘s sum these system of equation and we get: $y=-6$

We can now insert y as -6 and solve for x:

$3x-12=-3$

$x=3$

So, $x=3, y = -6$

Answer 2

Answer:

(3, - 6 )

Step-by-step explanation:

3x + 2y = - 3 → (1)

9x + 4y = 3 → (2)

Multiplying (1) by - 3 and adding to (2) will eliminate the x- term

- 9x - 6y = 9 → (3)

Add (2) and (3) term by term to eliminate x

0 - 2y = 12

- 2y = 12 ( divide both sides by - 2 )

y = - 6

Substitute y = - 6 into either of the 2 equations and solve for x

Substituting into (1)

3x + 2(- 6) = - 3

3x - 12 = - 3 ( add 12 to both sides )

3x = 9 ( divide both sides by 3 )

x = 3

solution is (3, - 6 )