Answer:
n = 8
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
Step-by-step explanation:
<u>Step 1: Define Equation</u>
6n + 7 = 55
<u>Step 2: Solve for </u><em><u>n</u></em>
- Subtract 7 on both sides: 6n = 48
- Divide 6 on both sides: n = 8
<u>Step 3: Check</u>
<em>Plug in n into the original equation to verify it's a solution.</em>
- Substitute in <em>n</em>: 6(8) + 7 = 55
- Multiply: 48 + 7 = 55
- Add: 55 = 55
Here we see that 55 does indeed equal 55.
∴ n = 8 is a solution of the equation.
Answer:
Amount invested at 8% is $9000 and amount invested at 18% is $21000.
Step-by-step explanation:
Let amount invested at 8% be x.
Let amount invested at 18% be y.
We get the 1st equation as:
........(1)
We get the second equation as:

=> 
or getting rid of the decimal by multiplying by 100 on both sides.
........(2)
Multiplying (1) by 8 and subtracting from (2) we get
So, y = 21000
And 

So, x = 9000
Therefore, amount invested at 8% is $9000 and amount invested at 18% is $21000.