Expression with Variables

IMPORTANT

Expression with Variables: Overview

This topic covers concepts, such as, Algebraic Expressions with Variables, Attributes of a Simple Algebraic Expressions, Like Terms of an Algebraic Expression & Unlike Terms of an Algebraic Expression etc.

Important Questions on Expression with Variables

EASY
IMPORTANT

Please read the following paragraph and answer the question at the end:
We learnt in arithmetic that we can find value of expressions like (2 x 10) + 5, 3 x 100 + 2 x 15  using BODMAS. These expressions are formed by using numbers like 2, 3, 4 and  so on. To form expressions we use all 4 operations like addition, subtraction, multiplication and division. For example, to form (2 x 10) + 5, we have multiplied 2 by 10 and then added 5 to the product. These are all arithmetic or number expressions.
Expressions can be formed using variables too. Like  x + 10 or 2x + 6 or y-100 etc. These expressions using variables are obtained  by operations of addition, subtraction, multiplication and division on variables. For example, the expression x + 10 is obtained by adding 10 to variable x.
We also know that variables can take different values; they have no fixed value. But they are numbers. That is why as in the case of numbers, operations of addition, subtraction, multiplication and division can be used in case of variables as well.
Please also note that while a number expression like 2 x 3 + 6 can be immediately evaluated, expression with variable like 2x + 5 can not be evaluated until the value of the variable is known. 
Based on above paragraph, select the correct statement?

EASY
IMPORTANT

Please read the following paragraph and answer the question at the end:
We learnt in arithmetic, that we can find value of expressions like (2 x 10) + 5, 3 x 100 + 2 x 15  using BODMAS. These expressions are formed by using numbers like 2, 3, 4 and  so on. To form expressions, we use all 4 operations like addition, subtraction, multiplication and division. For example, to form (2 x 10) + 5, we have multiplied 2 by 10 and then added 5 to the product. These are all arithmetic or number expressions.
Expressions can be formed using variables too. Like  x + 10 or 2x + 6 or y-100 etc. These expressions using variables are obtained  by operations of addition, subtraction, multiplication and division on variables. For example, the expression x + 10 is obtained by adding 10 to variable x.

Identify which one of the following is an expression with variable?

EASY
IMPORTANT

If a=2, b=3 and c=4 then the value of a3+b3+c3+3abc is _____ .

MEDIUM
IMPORTANT

Omar helps his mother 1 hour more than his sister does. If Omar helps his mother for A hours then write the value of A. (Take the variable as x)

HARD
IMPORTANT

Write the expression: Area of the rectangle with length k units and breadth n units is P square units then find P.

MEDIUM
IMPORTANT

Choose a letter x, y, z, p etc...., wherever necessary, for the unknown (variable) and write the corresponding expressions:

The perimeter of an equilateral triangle, if side of the triangle is m.

EASY
IMPORTANT

Write algebraic expressions for 10 divided by q in pq form.