The goal is to find the value of C.
Whatever we do to one side of the equation, we do to the other. Let's get all the terms with C on one side. We subtract 2 C from both sides. 4 C minus 2 C is 2 C. So we have 2 C= 10. Now we solve for C. 2 C means 2 * C. To undo multiplication, we divide. We can divide both sides by two. The twos cancel out leaving just C. 10 / 2 is 5. So c equals 5.
Let's look at a different problem. We have 9 a + 30 = 120. First we get the term with a by itself. We can subtract 30 from both sides. This leaves 9 a on the left. 120 - 30 is 90. Our equation is 9 a= 90. Now we find a. 9 a means 9 * a. We divide both sides by 9. We're left with a on the left. 90 / 9 is 10. So a equals 10. This equation has variables and numbers on both sides. Let's get all the p terms on the left. We subtract p from both sides. 5 p minus p gives us 4 p. Now we get the numbers on the right side. We subtract 901 from both sides.
101 minus 901 is 100. So we have 4 P = 100. We solve for P. Since P is multiplied by 4, we divide both sides by 4. 100 / 4 is 25. So P equals 25.
We've solved these equations by isolating the variable. Performing the same operation on both sides keeps the equation balanced.