Introduction to Algebra (Part II)

     Today we will see how to deal with Multiplication & division in Algebra

                                    We go with one example

We get the answer 2, right?

Because, 2 x 4 = 8, very Easy…..

In this puzzle we use empty box to represent the unknown value that we have to find.

But, in Algebra, we don’t use blank boxes, we use letters   (usually x or y, or any letter is fine) so we write.

But, ‘X’ looks like ‘x’ …. So it may confuse!!

So in algebra we don’t use the multiply symbol (x) between the numbers & letters instead we directly put the number next to the letters to mean multiplication.

                 4x = 8

Read as “four x equals to 8”

Means that: four x’s make 8.

 

After solving we get   x= 2  

Why we use letter in Algebra?

Because, it is easier to write a letter instead of drawing empty box. It is more relevant in reading mathematical statement. Also it permits use of different letters if the unknowns are more than one.

How to get values of unknowns?

Follow these step by step approaches to solve.

• ·        Work out “what to remove to get ‘x=…..’ “
• ·        Remove it by “doing the opposite” ( Adding opposite Subtraction & Multiplication opposite division, vice versa)
• ·        Do this on both sides and
• ·        Get the answer

Have an example.

(Quick check:  2 x 4 = 8)

Why do we divide by 4 on both sides?

Note: To keep the Balance

Another Example

Let’s take some complicated examples

         Practice Problems:

i) x/3 + 2 = 5          ii) x/5 - 2 = 3

iii) x/4 +5 = 9          iv) 3x = 27

Next Blog on "Transposing in Algebra"

see you then bye.....