Can you help? I need this by tomorrow!!

Question

I need help with my math homework! Please, show your work!!

1. This one seems pretty easy. I just need to know how to tell whether or not a set of coordinates is a function. I can't remember though...

2. What is the domain in

h(x)= 8x/x(x^2-81)

3. Evaluate g(n-3) if g(x)= x^2-2/5x

4. Find an equatin in slope-intercept form of the line that has slope 5 and passes through point A(4, -5).

a. y=5x 25 b. y=-5x-25 c. y=25x-5 d. y=5x-25

5. Determine the standard form of the equation of the line that passes through (2,7) and (-6,0).

Answer 1

1. you first question is confusing, but if you mean a set of coordinates like xyz coordinate system, just make sure they are all independent so like if they're all 90 deg apart from each other, (or if you are in linear algebra make sure they all have a pivot in each row , and if your in normal algebra/trig/calc etc ignore that.)

2. domain (i'm not breaking out any paper and pencil, this is just by sight, so you may wanna check with another answer to make sure i don't miss one )

(negative infinite, -9) U (-9,0) U (0,9) U (9, infinite)

U = union (i'm not sure if your using that or not, if not use the below)

or you can say whenever x does NOT equal : 0, -9, 9

3. just replace all x with n-3.

g(n-3) = [(n-3)^2-2]/[5(n-3)]

just simplify that, which sorry i'm too lazy to do.

4. just point slope equation

y-y1 = m(x-x1)

y- (-5) = 5 ( x- 4)

y+5 = 5x -20

y=5x-25  so i think that's a, but your missing the "+" on that choice :)

5. i hate standard forms, but if it's : ax + by = c

find slope:

change of y/change of x

7/8 = m = slope

use point slope again (there's a better way to do this so it's simplier but i forget)

y-7 = 7/8 (x-2)

y-7 = 7/8 x - 14/8

i'm sure you can rearrange that, hopefully.

btw there are certain tutor websites that can help you with this.

some good ones are tutor.com and brainfuse

and you would wanna check my answers since i've last touched any algebra about uh... 3-4 years ago?

Answer 2

for your following question

Find an equation in slope-intercept form of the line that has slope 5 and passes through point A(4, -5).

soln: here you need to find intercept(C)in the equation  of the form y=mx+c here x=4, y=-5 and m(slope)=5 so solve for c like

-5=5*4+C

-5-20=C so C= -25

equation will b

Y=5x-25