X/3 + 2y/3 = - 1 and x-y/3=9 solve. by elimination method

X=51/7, Y = - 36/7

Step-by-step explanation:

X/3 + 2y/3 = - 1 equ 1

X - y/3 = 9 equ 2

eliminate X/3.

X/3 + 2y/3 = - 1 ... x 1 (co-efficient of X in equ2)

X - y/3 = 9 ... x 1/3 (co-efficient of X in equ1)

X/3 + 2y/3 = - 1 equ 3

-

X/3 - y/9 = 3 equ 4

0 + 7y/9 = - 4

y = - 36/7

(input the value of y into equ 4)

X/3 - y/9 = 3

X/3 - (-36/7) / 9 = 3

X/3 + 36/63 = 3

X/3 = 3 - 36/63

X/3 = 153/63

63X = 459

X = 459/63

X = 51/7.