This would be easy for you if you know what the slope intercept form is. y = mx + b this is the formula. M is where you put the slope and b is where the y-intercept goes. Now let's plug the numbers in. The slope you said is -23 so that goes into the place of m. X is the variable. I'll give you an example. Say Mary put $100 into her bank account and every week she took 23 dollars. x would the number of weeks because it can change. So back to plugging the numbers in. This is what it will look like when we put -23 in. y = -23x + b. As we said above, b is the y-intercept. This is the point where the line on the graph crosses the vertical line, which is y. x is the horizontal line. You said the y-intercept is -4 so the line crosses the vertical line at the point -4. Plug this number into our formula, y = -23x + -4. There you go! We are finished making our slope intercept form equation. I hope you understood, and good luck to you in the future.
The question is somewhat confusing but assuming you mean where the submarine is after moving up 7 meters then down 38 meters the submarine would now be located 56 meters below sea level
