3x+7-5x=8
-2x+7=8
-2x=1
X=-1/2
y=3(-1/2)+7
y=-1.5+7
y=5.5
1200 ÷ 4 = 300
Each person will receive 300 stock cards.
This looks like a simple arithmetic series. Each term is 7 greater than the previous term.
Therefore, the Nth term is 17 + 7N.
For example, the first term is 17 + 7*1 = 17 + 7 = 24.
The second term is 17 + 7*2 = 17 + 14 = 31
etc...
And the 500th term is 17 + 7 * 500 = 17 + 3500 = 3517