Let's do it step by step:
First we need to understand that moving upwards would be addition to y-coordinates, while moving downwards would be deduction to the y-coordinates.
Moving to rightwards would be addition to x-coordinates and leftwards would be deduction to x-coordinates.
As we moved down by 1 unit and up for 2 units, it means that we are originally upward for one unit and downward by 2 units, which makes downwards for 1 units and would be -1 to the y-coordinates:
(-3,1 -1)
=(-3,0)
Therefore the start would be (-3,0).
Hope it helps!
Yes, Bobby will have enough money if he saves for 9 weeks. You can find this through either substituting w for 9 in the equation, or solving the equation itself.
Substituting:

Substitute w for 9.

Simplify.

Solve.
255 is greater than 250, so yes, he will have enough money saved.
Solving the equation:

Original Equation

Subtract 30 from both sides.

Divide both sides by 25.
The number of weeks he needs is 8.8. When rounding it up, you get 9.
14 hits
8 divided by 2 = 4 hits
So
28 divides by 2 = 14