math
posted by lisa on .
write the slop  intercept form of the equation wiht the given slope and intercept
slope:2/5 xint=4.5
i knwo how to do it with yint
but how doyou do it with x int?

y = mx + b, and you're right, we do not know the yintercept here.
so, y = (2/5)x + b.
They tell us the Xintercept is 4.5. How does this help us? The xintercept is where it crosses the xaxis. At that point, y = 0. So, the line crosses the point (4.5,0).
So, now we substitute in 0 for y and 4.5 for x:
0 = (2/5)(4.5) + b.
We can solve for b, and we get
b= 9/5.
So, we now have our yintercept, and use y = mx + b.
Does this make sense?? 
thank you =D

you're welcome!