Asked by George

x is partly constant and partly varies as y when y=5, x=1 and when y=7, x=8. find the equation connecting them. find x when y=11
Answered by oobleck
x = a + by
So, using the given points,
a + 5b = 1
a + 7b = 8
Now just solve for a and b, and then plug in y=11.