Question

Simultaneous equation:
Solve:

2x-3y=11
5x+2y=18

Answer 1

2*2x-2*3y=2*11-------------------------(1)
3*5x+3*2y=3*18------------------------(2)
add equation(1)&equation(2)
_____________________________
4x+15x=22+54
19x=76
x=4
put the value of x in equation(1)
2*2*4-2*3y=2*11
16-6y=22
16-22=6y
6y=-6
y=-1
x=4

Answer 2

x—2 equations combined: 2(2x - 3y) + 3(5x + 2y) = 2(11) + 3(18) 4x - 6y + 15x + 6y = 22 + 54 19x = 76 x = 4 y—1st equation, substitute x: 2(4) - 3y = 11 8 - 3y = 11 3y = - 3 y = - 1 Answer: x = 4, y = - 1 Proof—2nd equation: 5(4) + 2(- 1) = 18 20 - 2 = 18 18 = 18