You are told that y=-5, so just use that value for y in the second equation...
5x+4(-5)=-20
5x-20=-20
5x=0
x=0 so the solution, when the lines intersect, is the point (0,-5)
6 minutes maybe. I am not sure sorry
a) 67=50+17
50×7+17×9=350+153=503$
b) 123=50+50+23
50×7+50×9+23×10=350+450+230=1030$
Answer:

General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtraction Property of Equality
<u>Algebra I</u>
- Functions
- Function Notation
<u>Calculus</u>
Derivatives
Derivative Notation
Antiderivatives - Integrals
Integration Constant C
Integration Rule [Reverse Power Rule]: 
Integration Property [Addition/Subtraction]: ![\displaystyle \int {[f(x) \pm g(x)]} \, dx = \int {f(x)} \, dx \pm \int {g(x)} \, dx](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cint%20%7B%5Bf%28x%29%20%5Cpm%20g%28x%29%5D%7D%20%5C%2C%20dx%20%3D%20%5Cint%20%7Bf%28x%29%7D%20%5C%2C%20dx%20%5Cpm%20%5Cint%20%7Bg%28x%29%7D%20%5C%2C%20dx)
Integration Property [Multiplied Constant]: 
Step-by-step explanation:
<u>Step 1: Define</u>
<em>Identify</em>


<u>Step 2: Integration</u>
<em>Integrate the derivative to find function.</em>
- [Derivative] Integrate:

- Simplify:

- Rewrite [Integration Property - Addition/Subtraction]:

- [1st Integral] Integrate [Integral Rule - Reverse Power Rule]:

- [2nd Integral] Integrate [Integral Rule - Reverse Power Rule]:

- [3rd Integral] Rewrite [Integral Property - Multiplied Constant]:

- [3rd Integral] Integrate:

Our general solution is
.
<u>Step 3: Find Particular Solution</u>
<em>Find Integration Constant C for function using given condition.</em>
- Substitute in condition [Function]:

- Substitute in function value:

- Evaluate exponents:

- Evaluate natural log:

- Multiply:

- Add:

- Simplify:

- [Subtraction Property of Equality] Isolate <em>C</em>:

- Rewrite:

- Substitute in <em>C</em> [Function]:

∴ Our particular solution to the differential equation is
.
Topic: AP Calculus AB/BC (Calculus I/II)
Unit: Integration
Book: College Calculus 10e