Question

Solve the simultaneous equations

2y - 5x = 9
4y + 3x = 5
Do not use trial and improvement

Answer 1

x = -1, y = 2

Explanation:

2y - 5x = 9

4y + 3x = 5

eliminate one of the variables by multiplying the equations and then adding them together.

3(2y - 5x = 9)

5(4y + 3x = 5)

6y - 15x = 27

20y + 15x = 25

26y = 52

y = 2

now input the value of y into one of the original equations to find x.

8 + 3x = 5

8-5 = 3

x = -1

Answer 2

y = 2, x = -1

Explanation:

2y - 5x = 9

2y = 9+5x

y = (9+5x) /2

4y + 3x = 5

4((9+5x) /2) + 3x = 5

13x + 18 = 5

13x = -13

x = -1

y = (9+5x) /2

y = (9+5(-1)) /2

y = 2