Question

Please explain how to do this problem 8c=5c+21

Answer 1

Answer:

c = 7

General Formulas and Concepts:

Pre-Algebra

• Order of Operations: BPEMDAS
• Equality Properties

Step-by-step explanation:

Step 1: Define equation

8c = 5c + 21

Step 2: Solve for c

1. Subtract 5c on both sides:                    3c = 21
2. Divide 3 on both sides:                          c = 7

Step 3: Check

Plug in c into the original equation to verify it is a solution.

1. Substitute in c:                    8(7) = 5(7) + 21
2. Multiply:                               56 = 35 + 21
3. Add:                                     56 = 56

Here we see that 56 does indeed equal 56.

∴ c = 7 is a solution of the equation.

Answer 2

To solve for c, you need to isolate this variable.
Start by moving all the terms that are the same to one side.
8c and 5c are like terms. To move the 5c to the side of 8c, subtract.

8c=5c+21
-5c -5c
—————-
3c=21

To further isolate the variable, divide both sides by 3. This takes the coefficient away from c.

3c=21
—- —-
3 3

c=7

You can check by plugging your answer back in.
8(7)=5(7)+21
56=35+21
56=56
Therefore, this answer is correct.

c=7

I hope this helps! Comment if you need any more explanation and I will get back to you ASAP!