Question

2 0
doctor_will617
A linear function L is defined so that L(5)=7 and L(-1) =25. Find a formula for L of the form L(x)=mx+b. Then graph L, showing both intercepts and labeling them with their coordinates

Answer 1

Ok well lets figure out what the points are first:

when x=5, L(5)=7 so (5,7)

when x= -1, L(-1) = 25 so (-1,25)

now we just have to find the slope (m). Slope is just the Rise over Run or (L(-1) - L(5)) / (-1 - 5)
which now gives us:

m = (25-7) / (-1-5) = 8/(-6) = -4/3

so you have L(x) = -4/3 (x) + b

plug in one of your points, lets do (5,7)

7 = (-4/3)(5) + b
7= (-20/3) + b

isolate the (b) and you get

b = 1/3

so you're equation for the line is: L(x) = (-4/3)(x) + (1/3)

Answer 2

isn't it 18/-6=-3

Answer 3

for the slope

Answer 4

HAHA OH MAN you're right it should be -3

Answer 5

but you get the gist right?

Answer 6

yup thanx