Question

Using the matrix solve the following simultaneous equations
2x+5y=18
x-3y=-2

Answer 1

2x+5y=18 equ(1)

x-3y=-2 equ(2)

from equ (2) make x the subject of the formula

x=-2+3y

substitute x=2+3y in equ (1)

2+(-2+3y)+5y=18

-4+6y+5y=18

6y+5y=18+4

11y/11=22/11

y=2

substitute y=2 in equ(2)

x+3(2)=-2

x-6=-2

x=-2+6

x=4

x=4 and y=2