Write 2 equations
and show your work
plz me asap i need

You are asked to define variables that "model the situation" without being told what you care about in the situation. For that purpose, the variables you have chosen, ...

are completely appropriate. Your choice will give rise to two equations, already solved:

___

However, that is not going to be helpful for Part B.

In Part B, you're asked for the number of quarters. You might expect that choosing a variable to represent this quantity would be helpful, and you'd be right. For a variety of reasons, choosing another variable to represent the number of dimes is also helpful. Now, we have the definitions

The corresponding system of equations is ...

Since you're only interested in the number of quarters, it can be convenient to choose a solution method that focuses only on the q variable. Here, we'll multiply the first equation by -0.10 and add the result to the second equation. That eliminates d and gives an equation only in q.

  -0.10(q +d) +(0.25q +0.10d) = -0.10(90) +(17.55)

  0.15q = 8.55 . . . . . simplify

  8.55/0.15 = q = 57 . . . . . . divide by the coefficient of q to find the solution

Dylan has 57 quarters in his bank.

Comment on "this situation" problems

As you have discovered, modeling a particular "situation" needs to be informed by the aspect(s) of the situation that you care about. Many modern math texts ask for a model of "this situation" without bothering to tell you that crucial piece of information.

I find it unfortunate, and not particularly instructive in good critical thinking practice or problem solving technique.

Here, we found it helpful to read ahead for clues as to what the problem is really about. That will often be a helpful approach.

yo answer should be 6 if im not mistaken

step-by-step explanation:

hello from mrbilldoesmath!

answer:

the domain is the set { -2, 0, 2, 3}

discussion:

the domain is the set of x values in the ordered pairs (x,y). taking the x, or first component, of each ordered pair gives   -2, 0, 2, 3.

you,

mrb