3x + 5y = 1 . . . . . . . . (1)
7x + 4y = -13 . . . . . . .(2)
(1) x 7: 21x + 35y = 7 . . (3)
(2) x 3: 21x + 12y = -39 .(4)
(3) - (4) = 23y = 46
y = 46/23 = 2
Answer: 2x-6
Work Shown:
john = x
sam = x-3 since he scored 3 fewer than john
rob = 2*(sam) = 2(x-3) = 2*x-2*3 = 2x-6
Answer:
Negative numbers are used in navigation and directions determination
