Hi there. In this math education post, I cover solving basic linear equations (with no y-intercept). This topic is suitable for middle school mathematics students (grade 6, 7, 8).
The main idea when it comes to algebra is to solve for unknowns. When it comes to x + 7 = 10, the unknown x comes to 3. With linear equations solving for unknowns involves multiplication, division, addition and subtraction.
Example One
What is the value for x in the equation 5x = 30?
With this question look at more like 5 times something gives you thirty. Knowing your multiplication skills can lead you to the answer of 6 for the value of x. Another way to obtain the number 6 for x is doing 30 divided by 5.
Example Two - Negative Number Answer
Determine the value of x from the equation -9x = 99.
You can read this question as negative nine multiplied by something to equal 99. Dividing both sides by negative 9 gives x = -11. Remember that a positive and a negative number in division gives a negative answer/quotient.
Example Three - Fractional Answer
Sometimes the answers are not whole numbers. It can come in as a fraction (improper fraction usually) or a decimal.
Solve for the value of x in the equation 5x = 2.
If you read it as 5 times something gives you two, the answer may not be obvious. Note that when it comes to solving for x we are solving for 1x or a single x. If 5x = 2 then x has to be 2 divided by 5.
The answer for x would be 2/5 or 0.4 as a decimal. Decimal values are okay for answers as long as it's terminating.
Example Four
What is the value of x in 3x = 10?
Dividing both sides by 3 gives 10/3 which is an improper fraction. You can convert this into a mixed number which is 3 1/3. A decimal version for this answer is okay and long as you put a line on top of the 3 after the decimal in the number 3 and 3 tenths (3.3).
Thank you for reading.
