I am very sorry, but the question is not clear enough for someone to answer it.
You would just write f(x) (f of x) in for y: f(x) = 7x + 8.
Hope it helps.
First let us assume all black cards, the numbers that will
result in 24 is:
2 * 12
3 * 8
4 * 6
Similar case with the red cards:
-2 * -12
-3 * -8
-4 * -6
Assuming the product can be negative, so we can also take
the combination of two cards (1 red and 1 black):
2 * -12
3 * -8
4 * -6
-2 * 12
-3 * 8
-4 * 6
<span>So there are a total of 12 combinations.</span>
No not always sometimes you have to reduce it.