given an x y table what is the value of y when x = 0

Question

given a table x = 3,5,7 and y = 5,-3,-11 if y is a linear function of x, what is the value of y when x = 0

 

 

Answer 1

x=3, y=5

x=5, y=-3

x=7, y=-11

as x increases by 2, y decreases by 8

if x increases by 1, y decreases by 4

if x=4, y=1

if x=6, y=-7

if x=2, the previous y must be 4 more, or y=9

if x=1, the previous y must be 4 more, or y=13

if x=0, the previous y must be 4 more, or y=17

 

 

Answer 2

      x            y      

      3            5

      5           -3

      7          -11        Notice that x keeps increasing by 2 and y increases by -8. Then the slope is -8/2 = -4.

Now, you can write the equation of the line using the Point-Slope form.

y - y₁ = m(x - x₁)     Let's use the point (3,5)

y - 5 = -4(x - 3)

y - 5 = -4x + 12

y = -4x + 17

Let x = 0

y = 17    (0,17)