posted by milly .
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?
v = 4d
5d+3v = 3213
5d+3(4d) = 3213
17d = 3213
d = 189
v = 756
so, d+v = ?
its 5 grade math, can you make it more understanding
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?
I was wondering how to do it with bar graphs?