Math Guide

Introduction


                     In grade7 algebra, beside numerals we use symbols and literals in placeof unknown numbers to make a statement. Grade7 Algebra consists of Arithmetic problems. Grade7 algebra also consisting of both numerals andliterals. The algebraic expression can be defined as is an expression involving numbers and letters, multiplied together.


Topics under grade 7 algebra


  • Literals
  • Constant
  • Variable
  • Algebraic Expression
  • Arithmetic expression

Literals:

The letters that is used to represent the numbers is called as Literals.

Example:

The sum of two variables is 12. It can be written as x + y = 12. Here, x,y are the literals.

Constant:

A variable that has fixed numerical value is called as constant.

Example:

4,7, 8/5 are constants.

Variable:

  A term or quantity that has different numerical values is called as variable. It can be represented as x, y, z etc.

Algebraic expression:

The Algebraic expression is combination of variables, numerals and arithmetical expression .

Example:

The algebraic expressions are, 4x + 5y = 12

Arithmetic expression:

The combination of numbers formed to using arithmetic operations is called as arithmetic expression.

Example:

7 - 5 = 2, 6 + 5 = 11. These are some of the arithmetic expression.


Practice problem for grade 7 algebra


Practice problem 1:

Classify into arithmetic expression and algebraic expression.

1) 2 + 3 = 5 2) 7x + 4y = 15 3) 4x + 3y = 10 4) 8 + 3 = 11

Solution:

Arithmetic expression:

1) 2 + 3 = 5.

2) 8 + 3 = 11.

Algebraic expression:

1) 7x + 4y = 11.

2) 4x+ 3y = 10.


Practice problem 2:

Multiply the given two expressions (x + 3) (x – 4).

Solution:

First expression is (x + 3)

Second expression is (x – 4)

Multiply, (x + 3) (x - 4) = x2 + 3x - 4x – 12

                                 = x2 + 3x - 4x – 12

Answer:

The final answer is x2 + 3x - 4x – 12.


Practice problem 3:

Add the given two algebraic expressions (3x + 2) and (5x – 12)

Solution:

Given expressions are (3x + 2) and (5x – 12)

Adding the two expressions, we get

            = 3x + 2 + 5x – 12

            = 8x – 10

Answer:

The final answer is 8x – 10


Practice problem 4:

Subtract the algebraic expressions (2x + 12) and (8x – 14)

Solution:

Given two expressions are (2x + 12) and (8x – 14)

Subtract the two algebraic expressions, we get

(2x + 12) – (8x – 14) = 2x + 12 – 8x + 14

                              = - 6x + 26

Answer:

The final answer is – 6x + 26