Posted by milly on .
the cost of 5 similar digital cameras and 3 similar video cameras is $3213 each video camera costs 4 times as much as each digital camera. john buys a digital camera and a video camera. how much does he pay?

math 
Steve,
v = 4d
5d+3v = 3213
5d+3(4d) = 3213
17d = 3213
d = 189
v = 756
so, d+v = ? 
math 
milly,
its 5 grade math, can you make it more understanding

math 
PsyDAG,
The price of 4 digital = one video.
5 digital + 3 video = 3213
Substitute 4d for v in second equation and solve for d.
5 digital + 3(4 digital) = 3213
Insert that value into the first equation and solve for v. Check by inserting both values into the second equation. Since John buys one of each, add the two values.
Does that make it clearer? 
math 
Anonymous,
I was wondering how to do it with bar graphs?