Question

One number is 5 more than another number. Find these numbers if their product is -3.

Answer 1

I just need to know how to set up the problem :)

Answer 2

lets call one number x and the other y

one number is 5 more than another number
x = 5 + y

so we have one equation x=5+y

and we know x and y has a product of -3=>xy=-3

so the other equation is xy=-3

we know x=5+y so plug this x into the one that is in xy=-3
so we have
(5+y)y=-3

Answer 3

to setup:

x= 5+y (one number is 5 more than the othe rnumber)
xy = -3 (their product is -3)

Answer 4

Did you get -5+_ sqrt13/2??

Answer 5

(5+y)y=-3
5y+y^2=-3
y^2+5y=-3
y^2+5y+(5/2)^2=-3+(5/2)^2
(y+5/2)^2=-3+25/4
(y+5/2)^2=-3*4/4+25/4
(y+5/2)^2=-12/4+25/4
(y+5/2)^2=13/4
take square root of both sides

y+5/2=plus or minus sqrt{13/4}

y+5/2=plus or minus sqrt{13}/2

y=-5/2 plus or minus sqrt{13}/2

so we have
y=-5/2 + sqrt{13}/2 or y=-5/2 - sqrt{13}/2

Answer 6

and so x=5+y

so just plug your two y's into there to find your x's

Answer 7

Thank you myininaya and laksmanv :)

Answer 8

np
crazy how they didn't choose a word problem that worked out more nicely