Question

2x-5y=9
3x+4y=2
Simultaneous equation find x and y

Answer 1

x = 2

y = -1

Explanation:

2x - 5y = 9

3x + 4y = 2

find x in terms of y using the first equation

2x - 5y = 9

2x = 9 + 5y

x = 4.5 + 2.5y

substitute x for 4.5 + 2.5y in the second equation

3x + 4y = 2

3(4.5 + 2.5y) + 4y = 2

13.5 + 7.5y + 4y = 2

13.5 + 11.5y = 2

11.5y = 2 - 13.5

11.5y = -11.5

y = -1

now substitute y for -1 in the first equation

2x - 5y = 9

2x + 5 = 9

2x = 9 - 5

2x = 4

x = 2