How to solve equation with substitution

equation. please help.

the first equation"

the graph of. 3y-16x=9 and then I have to give the equation in standard form

rest. The current unit that our teacher has us on so far is centripetal motion, and I can't recall being taught how to solve this. File attached below shows my work so far, I don't necessarily need the work done for me, but I just want to be put on the right track, such as an equation to start with or what I need to look for. The answer I got was clearly incorrect for part a (which is what I need help with), so please help me get going in the right direction.

26. Solve the equation $98.26 + d = $156.75 to find how much more money Gabriel needs.

em. Joe is taking trip in the summer of 2020. He owes $3745. He opens a new account to start saving money. He plans to put $400 into the account every month. The account accrues 2% on the last day of every month. How long will it take him to reach his goal of $3745. Exact answer not rounded.

lly so that in six years the balance of the account will be $4000?" How do I set up the equation for this and then what do I do to solve it and get the answer to the question?

that models profit earned is D = n(54 – n) – 10n. I need to find the vertex of this equation, and what does the vertex tell me about this situation.. For what x-values is the function increasing? Decreasing? What does this mean in terms of daily profit for Water World? Rewrite the function in vertex form. . Solve the equation 0 = n(54 – n) – 10n for n. Describe your solution method. How are the solutions from part (e) related to the graph of this function? Are the solutions real or complex? How do you know? What do the solutions from part (e) tell you about this situation?