2007-01-24 08:06:04 · 8 answers · asked by Anonymous in Education & Reference ➔ Homework Help
You just plug in x to 5, so it'll look like this:
7.8x - 17.2
7.8(5) - 17.2 <<< Plug in 5 for x
39 - 17.2 <<< Multiply 7.8 to 5
21.8 <<< Subtract 39 to 17.2
So 21.8 is your solution.
2007-01-24 08:13:40 · answer #1 · answered by Christina 3 · 0⤊ 0⤋
OK; well to start off you know that x=5...right?
Well...if the equation is 7.8x-17.2, then you have to subsitute x for 5 since x=5.
This will give you 7.8(5)-17.2.
Now, you need to multiply 7.8 and 5 together.
7.8 8x5=40
x 5 7x5=35+4(from the 40)=39
------
390
Now insert the decimal one decimal place...
39.0
Now you subtract 39.0 from 17.2....
39.0
- 17.2
--------
21.8 and you get 21.8!!!!!!!!!
(You CAN put it on a caluclator...but...it is not good to be calculator dependent. =] )
2007-01-24 16:53:11 · answer #2 · answered by Anonymous · 0⤊ 0⤋
21.8. Just replace x with 5 multiply by 7.8 and subtract 17.2
2007-01-24 16:11:48 · answer #3 · answered by stargazer08 3 · 0⤊ 0⤋
17.8(5)-17.2: simply equals 21.8
2007-01-24 16:17:48 · answer #4 · answered by Venomous 2 · 0⤊ 0⤋
21.8=)
**Replace x with 5**
multiply 7.8 by 5
7.8 (5)=39
then SUBTRACT that answer {39} by 17.2
7.8(5) -17.5
or
"39 - 17.5"=21.8
^^giving u 21.8^^
=D
2007-01-24 16:11:46 · answer #5 · answered by keeka2 2 · 0⤊ 0⤋
It's 21.8
2007-01-24 16:10:15 · answer #6 · answered by Anonymous · 0⤊ 0⤋
21.8, but your real dumb if u can't do that yourself. you can do it on your standard calculator!
2007-01-24 16:15:21 · answer #7 · answered by ŤÏҒҒǻńỷ™ ♀ 2 · 0⤊ 0⤋
21.8
2007-01-24 16:13:14 · answer #8 · answered by Party's Queen'' 2 · 0⤊ 0⤋