# 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

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

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