Question

Identify the equation for the graph shown.
A)
y = x - 4
B)
y = 5x - 2
C)
y = 3x - 6
D)
y = 2x - 5

Answer 1

@fuzzfuzzgirl At what point line crosses the x axis?

Answer 2

2.5?

Answer 3

Good so this is the x-intercept.
X-intercept is the point where the line crosses the x-axis
Now tell what point the line crosses y-axis?

Answer 4

-5?

Answer 5

Is the answer D?

Answer 6

Yes

Answer 7

Because the y-intercept is -5

Answer 8

Let's not rush to the answer, How did you get this?

Answer 9

Because 2 crosses the x axis and in the equation there is a 2x and because -5 crosses the y axis and in the equation there is a -5

Answer 10

?

Answer 11

Nope that's not the way, We found x- intercept as 2.5 and y-intercept as -5
If a line has x-intercept a and y intercept b, then it's equation is
\[\frac x a+\frac y b=1\]
Now you write the equation for this line

Answer 12

What do you fill in for x, y, a, and b?

Answer 13

x and y are just x and y
a= x-intercept
b=y intercept

Answer 14

so x/2.5 + y/-5 = 1 ?

Answer 15

Yeah, now try to simplify this, you'll get the answer

Answer 16

2?

Answer 17

Share here, how did you simplify the equation

Answer 18

i just divided -5 by 2 so that's -2 ?

Answer 19

\[\frac x {2.5} +\frac y {-5}=1\]
\[\frac {x\times -2} {2.5 \times -2} +\frac y {-5}=1\]
\[\frac{-2x}{-5}+\frac{y}{-5}=1\]
\[-2x+y=-5\]
\[y=2x-5\]

Answer 20

Oh, I didn't think it would be that complicated.... is that the same formula you always use?