Maria buys 2 dozen pens at $7.20 a dozen. she then sells the pens at 80c each. calculate her profit

Can some one help me with this question: Solve 5x-22=20

Annette [7]

Answer: x = 8.4

Work: So, the goal of this equation is to get x by itself, and the first thing we need to do is get 22 out of that current side. To do that, we are going to add 22 on both sides, cancelling it on the side it's currently on. So, the new equation is 5x = 42. Now, we need to divide 5 on both sides, and like I said, I'll cancel on the side it's currently on. So, the answer is x = 8.4

I hope this helps, and Happy Holidays! :)

7 0

3 years ago

Read 2 more answers

10 points !!!!!! Help

Mars2501 [29]

Here’s a chart to help you.

5 0

3 years ago

Read 2 more answers

What expression represents the length of the rectangle ?

saul85 [17]

Answer:

rectangle had an area of x2+13x+36 square meters the length of x+9 meters. What expression represents the width of the rectangle?

Step-by-step explanation:

7 0

3 years ago

Need help please its Calculus. Ill give the 5 stars as well.

algol13

Answer:

$\displaystyle y = 2e^\bigg{\frac{x^3}{3}} + 1$

General Formulas and Concepts:

Pre-Algebra

Order of Operations
Equality Properties

Algebra I

Functions
Function Notation
Exponential Rule [Rewrite]: $\displaystyle b^{-m} = \frac{1}{b^m}$

Algebra II

Natural logarithms ln and Euler's number e

Calculus

Derivatives

Derivative Notation

Basic Power Rule:

f(x) = cxⁿ
f’(x) = c·nxⁿ⁻¹

Slope Fields

Separation of Variables

Solving Differentials

Integrals

Antiderivatives

Integration Constant C

Integration Rule [Reverse Power Rule]: $\displaystyle \int {x^n} \, dx = \frac{x^{n + 1}}{n + 1} + C$

Integration Property [Addition/Subtraction]: $\displaystyle \int {[f(x) \pm g(x)]} \, dx = \int {f(x)} \, dx \pm \int {g(x)} \, dx$

U-Substitution

Logarithmic Integration: $\displaystyle \int {\frac{1}{u}} \, dx = ln|u| + C$

Step-by-step explanation:

*Note:

When solving differential equations in slope fields, disregard the integration constant C for variable y.

Step 1: Define

$\displaystyle \frac{dy}{dx} = x^2(y - 1)$

$\displaystyle f(0) = 3$

Step 2: Rewrite

Separation of Variables. Get differential equation to a form where we can integrate both sides and rewrite Leibniz Notation.

[Separation of Variables] Rewrite Leibniz Notation: $\displaystyle dy = x^2(y - 1) \ dx$
[Separation of Variables] Isolate y's together: $\displaystyle \frac{1}{y - 1} \ dy = x^2 \ dx$

Step 3: Find General Solution Pt. 1

[Differential] Integrate both sides: $\displaystyle \int {\frac{1}{y - 1}} \, dy = \int {x^2} \, dx$
[dx Integral] Integrate [Integration Rule - Reverse Power Rule]: $\displaystyle \int {\frac{1}{y - 1}} \, dy = \frac{x^3}{3} + C$

Step 4: Find General Solution Pt. 2

Identify variables for u-substitution for dy.

Set: $\displaystyle u = y - 1$
Differentiate [Basic Power Rule]: $\displaystyle du = dy$

Step 5: Find General Solution Pt. 3

[dy Integral] U-Substitution: $\displaystyle \int {\frac{1}{u}} \, du = \frac{x^3}{3} + C$
[dy Integral] Integrate [Logarithmic Integration]: $\displaystyle ln|u| = \frac{x^3}{3} + C$
[Equality Property] e both sides: $\displaystyle e^\bigg{ln|u|} = e^\bigg{\frac{x^3}{3} + C}$
Simplify: $\displaystyle |u| = Ce^\bigg{\frac{x^3}{3}}$
Rewrite: $\displaystyle u = \pm Ce^\bigg{\frac{x^3}{3}}$
Back-Substitute: $\displaystyle y - 1 = \pm Ce^\bigg{\frac{x^3}{3}}$
[Equality Property] Isolate y: $\displaystyle y = \pm Ce^\bigg{\frac{x^3}{3}} + 1$

General Form: $\displaystyle y = \pm Ce^\bigg{\frac{x^3}{3}} + 1$

Step 6: Find Particular Solution

Substitute in function values [General Form]: $\displaystyle 3 = \pm Ce^\bigg{\frac{0^3}{3}} + 1$
Simplify: $\displaystyle 3 = \pm C + 1$
[Equality Property] Isolate C: $\displaystyle 2 = \pm C$
Rewrite: $\displaystyle C = 2$
Substitute in C [General Form]: $\displaystyle y = 2e^\bigg{\frac{x^3}{3}} + 1$

∴ our particular solution is $\displaystyle y = 2e^\bigg{\frac{x^3}{3}} + 1$ .

Topic: AP Calculus AB/BC (Calculus I/I + II)

Unit: Differentials and Slope Fields

Book: College Calculus 10e

6 0

3 years ago

Pls can some one help if you like

Snezhnost [94]

Slope is rise/run
gains 4m height for every 3secons
rise=4m
run=3sec
slope=4/3

if takes 54seconds t
54 times 4/3=72 meters

max height is 72 meteres assuming that it starts from the ground level

4 0

3 years ago

Maria buys 2 dozen pens at $7.20 a dozen. she then sells the pens at 80c each. calculate her profit​

Maria buys 2 dozen pens at $7.20 a dozen. she then sells the pens at 80c each. calculate her profit