1 to 45 is 45
90 divided by 2 is 45
135 divided by 4 is 45
180 divided by 4 is 45
all of them have the same relationship and a proportional to each other
You have two unknown rates, so we need to develop two equations to solve for these unknowns (based on the information given on the problem statement):
5x + 10y = 725
x + y = 100
By substitution, we get:
5x + 10(100 - x) = 725
5x + 1000 - 10x = 725
-5x = 725 - 1000
-5x = -275
x = -275/-5 = 55
100 - 55 = 45
Thus:
The mechanic who worked for 5 hours charged his time at $55/hr, and the mechanic who worked for 10 hours charged his time at $45/hr.
To verify, plug and chug the results back into the original equations:
5(55) + 10(45) = 725
275 + 450 = 725
725 = 725 [OK]
55 + 45 = 100 [OK]
Answer:
(4/3, 7/3)
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>
- Terms/Coefficients
- Coordinates (x, y)
- Solving systems of equations of using substitution/elimination
Step-by-step explanation:
<u>Step 1: Define Systems</u>
7x - y = 7
x + 2y = 6
<u>Step 2: Rewrite Systems</u>
Equation: x + 2y = 6
- [Subtraction Property of Equality] Subtract 2y on both sides: x = 6 - 2y
<u>Step 3: Redefine Systems</u>
7x - y = 7
x = 6 - 2y
<u>Step 4: Solve for </u><em><u>y</u></em>
<em>Substitution</em>
- Substitute in <em>x</em>: 7(6 - 2y) - y = 7
- Distribute 7: 42 - 14y - y = 7
- Combine like terms: 42 - 15y = 7
- [Subtraction Property of Equality] Subtract 42 on both sides: -15y = -35
- [Division Property of Equality] Divide -15 on both sides: y = 7/3
<u>Step 5: Solve for </u><em><u>x</u></em>
- Define original equation: x + 2y = 6
- Substitute in <em>y</em>: x + 2(7/3) = 6
- Multiply: x + 14/3 = 6
- [Subtraction Property of Equality] Subtract 14/3 on both sides: x = 4/3
The solution is y < -1/5
In order to find the answer to this problem, follow the order of operations for solving equations/inequalities.
444 + 555y < 333 -----> Subtract 444 from both sides
555y < -111 -----> Divide both sides by 555
y < -1/5
