# Choose the correct graph of the given system of equations: y + 2x = −1 and 3y − x = 4

An equation of degree 1 is called linear equations. The standard form of linear equations in two variables is ax + by = c, where a, b and c are constants.

## Answer: Option a) is correct.

Let's solve the system of linear equations in two variables.

**Explanation:**

The given equations are y + 2x = -1 --- (1) and 3y - x = 4 --- (2)

From equation (2), we get

3y - x = 4

x = - 4 + 3y --- (3)

To solve the system of linear equations we will substitute value of x = -4 + 3y equation (3) in equation (1) and solve for x.

⇒ y + 2 (-4 + 3y) = -1

⇒ y - 8 + 6y = -1

⇒ 7y = -1 + 8

⇒ 7y = 7

⇒ y = 1

Put y = 1 in equation 2

⇒ x = -4 + 3(1) = -4 + 3= -1

⇒ x = -1

We can use Cuemath's online system of equations calculator to solve the equations.

So, the solution to y + 2x = −1 and 3y − x = 4 is (-1, 1).