Question

Given the system below, determine the values of r,s and u that satisfy all three equations : r+2x-u=8 ; s+u=4 ; r-s-u=2.

Answer 1

r = 6

s = 2

u = 2

Explanation:

Given:

r + 2s - u = 8 ...........(1)

s + u = 4

or

s = 4 - u .........(2)

r - s - u = 2

or

r = 2 + s + u ................(3)

substituting 2 in 3, we get

r = 2 + (4 - u) + u

or

r = 6

substituting r in 1 we get

6 + 2s - u = 8

or

2s - u = 2 ..............(4)

substituting 2 in 4 we get

2(4 - u) - u = 2

or

8 - 2u - u = 2

or

-3u = -6

or

u = 2

substituting u in 2, we get

s = 4 - 2 = 2

hence,

r = 6

s = 2

u = 2