Question

solve system using elimination x + 2y = 7 and 3x - 2y = -3.

Answer 1

Elimination method :

The system of equations are

x + 2y = 7     → (1)

3x - 2y = - 3 → (2)

Since the coefficient of the y - term in two equations is same, i can eliminate these terms by adding the equations.

Write the equations in column form and add to eliminate variable y.

       x + 2y = 7

( + )3x - 2y = - 3

__________________

4x = 4

The resultant equation is  4x = 4 and solve it for x.

Divide each side by 4.

x = 4/ 4

Cancel common terms.

x = 1.

Substitute the value of x = 1 in equation 2 and solve for y.

3(1) - 2y = - 3

3 - 2y = - 3

Subtract 3 from each side.

- 2y = - 6

Divide each side by negative 2.

y = 3.

The solution is (1, 3).