Subtracting a negative integer is the same as adding a positive integer. Adding a positive integer to any number always makes the answer larger than the original number. Therefore, if you subtract one negative integer from another your answer will be always be *greater* than the integer you started with.
First question:
1. Set equations equal to each other so 5x-9=2x+6
2. Put x's on one side so that 3x=15
3. Divide by 3 so that x=15
4. Substitute 15 in for x so that y=2(15)+6
5. Solve for y so that y=36
6. Thus the equations intersect at (15,36)
Second question:
1. Since for lines y=mx+b, and m=slope=3 you only need to write an equation with slope 3
2. y=3x+b, b can be any number
If Bobby claims Peter started with 21 cards, then we'll work this into our equation.
21 - 3 (that he lost) = 18
18 / 2 (the half he gave) = 9
So this means that he did have 21 cards to begin with. Please reply to this with a list of the answers that can/could be checked!
I believe the answer is 2.222222222
