variables

[chelsie]

ok we have these problems all the time and i can not figure out how to do them

Find the values of all four variables in this system of equations.
(a) RrTr=96
(b) RpTp=72
(c) Rr=3Rp
(d) Tr+Tp=13

i know you have to solve for something first but i dont know which one or how to do it

 

[Mrspi]

ok we have these problems all the time and i can not figure out how to do them

Find the values of all four variables in this system of equations.
(a) RrTr=96
(b) RpTp=72
(c) Rr=3Rp
(d) Tr+Tp=13

i know you have to solve for something first but i dont know which one or how to do it

Just to simiplify the way this looks, I'm going to rename these variables:
let x = Rr
let y = Rp
let z = Tr
let z = Tp

Now, the equations can be written as
a) xz = 96
b) yw = 72
c) x = 3y
d) z + w = 13

Substitute 3y for x in equation a):
3yz = 96
yz = 32
Now, add this to equation b):
yz + yw = 32 + 72
yz + yw = 104

Factor a y out of the left side:
y(z + w) = 104

But, from equation d), we know that z + w = 13. So,
y*13 = 104
y = 8

Ok....now, you should be able to find the values of the remaining variables.

 

[chelsie]

Awesome Thanks a bunch