Algebra For Beginners

Описание: BrightMind21
   • Algebra For Beginners  
   / @brightmind-21  
1. What is Algebra?

Algebra is a branch of mathematics that uses letters (variables) to represent numbers.
It allows us to write equations and solve problems without knowing all the numbers right away.

Example:
If
𝑥
x represents the number of apples you have, then:

𝑥
+
3
=
7
x+3=7

means you have 3 more apples to reach a total of 7. Solving it gives
𝑥
=
4
x=4.

2. Basic Terms in Algebra

Variable: A letter that represents a number.

Example:
𝑥
,
𝑦
,
𝑧
x,y,z

Constant: A fixed number.

Example:
3
,
−
5
,
10
3,−5,10

Coefficient: A number multiplying a variable.

Example: In
5
𝑥
5x, 5 is the coefficient.

Expression: A combination of numbers, variables, and operations (like +, -, ×, ÷).

Example:
2
𝑥
+
3
2x+3

Equation: A statement that two expressions are equal.

Example:
2
𝑥
+
3
=
7
2x+3=7

3. Basic Operations in Algebra

Addition/Subtraction: Combine like terms.

2
𝑥
+
3
𝑥
=
5
𝑥
2x+3x=5x
7
𝑥
−
2
𝑥
=
5
𝑥
7x−2x=5x

Multiplication/Division: Multiply coefficients.

3
⋅
2
𝑥
=
6
𝑥
3⋅2x=6x
6
𝑥
2
=
3
𝑥
2
6x
​

=3x
4. Solving Simple Equations

Goal: Find the value of the variable.

Steps:

Simplify both sides of the equation.

Move variables to one side and constants to the other.

Solve for the variable.

Example 1:

𝑥
+
5
=
12
x+5=12

Subtract 5 from both sides:

𝑥
=
12
−
5
x=12−5
𝑥
=
7
x=7

Example 2:

3
𝑥
=
15
3x=15

Divide both sides by 3:

𝑥
=
15
3
=
5
x=
3
15
​

=5
5. Working with Fractions

Example:

𝑥
4
=
3
4
x
​

=3

Multiply both sides by 4:

𝑥
=
12
x=12
6. Tips for Beginners

Always do the same thing to both sides of an equation.

Combine like terms carefully.

Keep equations balanced: what you do on one side, do on the other.

Practice small steps before moving to big problems.