I need help with these problems: please read?

Question

heyy i need help with these problems. trust me these aren't all of the problems in the packet i am supposed to do, these are just the few i need help on. please don't tell me to 'go do my own work'. I came here for help and I am doing my own work. trust me there is like 50 problems, these are just the select few i don't understand.

thanks sooooooo much for your help!

1: 1/2h(x+y)=A, if h=8, x=12, and A=400, find y

2: the slope of a line= y*y - y

______

x*x - x for any two points in the coordinate plane. Find the slope of the line between the following ordered pairs

(5,10) and (3,6)

(7,20) and (-3,-10)

(8,15) and (8,25)

(10,9) and (15,9)

3. Using the Distance Formula on the coordinate plane, find the distance between the following points:

(6,4) and (2,1)

(0,0) and (5,10)

-5,2 and (7,-7)

THANKSSSS!

Answer 1

I am certain that we would be happy to answer your questions, but I think that you need to double-check that you have written them down carefully. Questions #1 is not written clearly and #2 doesn't make sense, so we can't answer it.

1. Is this

(1/2)*h*(x+y)=A

or

1/(2*h*(x+y)) = A??

If the first, then (1/2)*8*(12+y)=400 or 12+y=100 or y=88

If the second then 1/(2*8*(12+y)) = 400 or 1/(12+y)=6400 or 12+y=1/6400 or y = 12-1/6400 = 76799/6400

2. What line?  The equation for a line in cartesian coordinates will be of the form

y=mx+b

or something equivalent.

Slopes between points are easily computed as

(y2-y1)/(x2-x1)

(5,10) and (3,6): slope = (10-6)/(5-3) = 4/2 = 2

(7,20) and (-3,-10): slope = (20+10)/(7+3) = 30/10 = 3

(8,15) and (8,25): slope = (25-15)/(8-8) = undefined

(10,9) and (15,9): slope = (9-9)/(15-10) = 0

3. The formula is sqrt((x2-x1)^2 + (y2-y1)^2)

(6,4) and (2,1): sqrt(3^2+4^2) = sqrt(25) = 5

(0,0) and (5,10): sqrt(5^2+10^2) = sqrt(125) = 5*sqrt(5)

(-5,2) and (7,-7): sqrt(12^2 + 9^2) = sqrt(225) = 15

Good luck to you. One piece of advice: please use parentheses when needed to make your formulas unambiguous.

Good luck!