Math Guide

Pre algebra 1

Introduction of pre algebra1:


         Pre Algebra 1 is defined as the part of the mathematics which deals with the relation and operations. It also performs polynomials, number theory, arithmetic operations of addition and subtraction and also framing of the formula to solve some of the equation. Pre algebra 1 is considered seventh, eighth and ninth grade math. Pre algebra 1 includes areview of whole number arithmetic. It also introduce the integers, fractions, decimals and negative numbers. Factoring, exponents and square roots are also the important components of pre algebra 1. Let us see about the problems of equations in pre algebra 1.


Problems in pre algebra 1:


In a shop three persons, A, B and C purchased the following quantities of rice, wheat and sugar.

      Rice (Kg)         Wheat (Kg)          Sugar (Kg)

A       3                      2                          4

B        2                       3                          2

C       4                       5                          4

 Ifthey have paid respectively Rs.140, Rs.104 and Rs.196 for the purchasesmade, find the cost of 1 kg of rice, wheat and sugar.

Solution:

Let the sale price of 1 kg of rice be Rs.x, wheat be Rs.y and sugar be Rs.z, then we

get

3x + 2y + 4z = 140 (1)

2x + 3y + 2z = 104 (2)

4x + 5y + 4z = 196 (3)

Considering the equations (1) and (2)

(1)=>        3x + 2y + 4z = 140

(2) x 2 => 4x + 6y + 4z = 208

                – x – 4y = –68

                   x + 4y = 68 (4)

 Considering equations (2) and (3)

(2) x 2      4x + 6y + 4z = 208

(3)            4x + 5y + 4z = 196

                                y = 12

Substituting y = 12 in (4) we get

x + 4(12) = 68 or x = 68 – 48 = 20

Substituting x = 20, y = 12 in (1) we get

3(20) + 2(12) + 4z = 140 or

84 + 4z = 140

z = 56/4 = 14

x = 20, y = 12, z = 14

Rice = Rs.20 / Kg; Wheat = Rs.12 / Kg; Sugar = Rs.14/Kg.


Pre algebra (7 th grade) Example:


The following equation shows the total pages of notes White has in his notebook.

                                 p = 2h

 Thevariable h represents the number of hours he spends in class, and the variable p represents the total number of pages of notes in his notebook. After attending 3 hours of class, how many total pages of notes will Mason have in his notebook?

Choose the answer

1) 5 ,2) 6 , 3) 8, 4) 7