Steemkids lessons: Forming simple equations

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An equation is a mathematical sentence where two algebraic expressions are equal.
Equation shows that two expressions are equal to each other.
Example
3x + 5 = 20. This means that the right hand side is equal to the left hand side.

An equation in which the highest power of unknown is one is known as simple equation.

Examples are: x + 8 = 12; 3a + 6 = 10; 12 + b = 20

Forming simple equations

Simple word problems can be translated to algebraic equations.
Below is an example

1.) If a certain number is multiplied by 3, the answer is 12 more than the number. Represent this with an equation

Solution

Step 1: represent the unknown with a letter.
The unknown in this case is the number. So, we say the number is a.

The expression says that the unknown is multiplied by 3. That is 3a.
Also the answer is 12 more than the number.
3a = 12 + a
The equation has been formed as
3a = 12 + a.

2.) 5 times a number is added to 5 which give the result of 20.

identify the unknown and represent with a number*. We will represent the unknown with n.

The expression says that the number is added 5 times to 5. That is 5n + 5
Also it gives the result of 20. Which means that the number added 5 times to 5 is equal to 20.

The equation is formed as:
5n + 5 = 20

3) I have a certain amount, if I add 14 to it, the result will be 16. What is the amount I have.
solution
Let d represent the amount
d + 14 = 16

Solving simple equations

Solve the following equations:
5n + 5 = 20

The unknown in the equation is n.

Separate the unknown part from the known.
5n = 20 - 5

solve the known part
5n = 20-5
5n = 25

Divide both sides by the number attached to the unknown.
5n/5 = 25/5
n = 4

This means that the unknown in the equation is 4.

Example 2

Example 3

Example 4

Note: When a positive sign crosses over an equality sign it changes to negative and the other way round.
For example: 2 + s = 4 = s = 4 - 2
The positive sign in 2 changes to negative when it is crossing an equality sign.

Assignment

Section a
Form equations with the following expressions:

• Four times a number gives 40
• I have a number, double it and add 10 to it, and the answer will be 20.
• Twice a number is added to 5 and it gives 25 as the result.
• Ninety plus a number gives two hundred and one.

Section b
Solve the equations you have formed in section a.

Rules

This assignment should be done as a comment under this post.
In line with these adjustments made by @steemkidss assignment exclusively for the kids. The kids should only participate using their own personal account.

5 steem will be shared among all participants

Cc:
@ngoenyi
@steemkidss