Math

Quote:

7x-4y=18
5x+y=17

7x -4y = 18
5x + y = 17

from 2nd eq

y = 17 - 5x

plugging into 1st eq

7x - 4(17-5x) = 18
7x - 68 + 20x = 18
27x = 86
x = 86/27
y = 17 - 5(86/27) = 17 - 430/27 = 29/27