The document provides an overview of basic algebra concepts, focusing on solving equations for an unknown variable, commonly represented as 'x'. It explains methods like substitution to find solutions, along with examples of various algebraic equations. The document also briefly mentions the historical figure al-Khwarizmi, the founder of algebra.

1. What is Algebra about?
Quick Education

2. 5 + 2 = ?
Which one is true?
5 + 2 = 6
5 + 2 = 7
5 + 2 = 8

3. 5 + 2 = ?
5 + 2 = 6
5 + 2 = 7
5 + 2 = 8

4. 5 + ? = 7
Which one is true?
5 + 1 = 7
5 + 2 = 7
5 + 3 = 7

5. 5 + ? = 7
5 + 1 = 7
5 + 2 = 7
5 + 3 = 7

6. 5 + x = 7
Which one is true?
5 + 1 = 7
5 + 2 = 7
5 + 3 = 7

7. 5 + x = 7
5 + 1 = 7
5 + 2 = 7
5 + 3 = 7

8. x + 2 = 7
Which one is true?
4 + 2 = 7
5 + 2 = 7
6 + 2 = 7

9. x + 2 = 7
4 + 2 = 7
5 + 2 = 7
6 + 2 = 7

10. x + 2 = 7
What is x?

11. x + 2 = 7
X = 5

12. 5 + x = 7
What is x?

13. 5 + x = 7
X = 2

14. 5 + 2 = x
What is x?

15. 5 + 2 = x
X = 7

16. 5 + x = 7
This is algebra. Why?

17. 5 + x = 7
It’s because of the x.

18. 5 + x = 7
What do you think x is called?
Guess…

19. X
X is called the variable

20. X
X is also called the unknown. Why?

21. 5 + 2 = xBecause when you first start working on a problem,
you don’t know what x is until you think about it.
This one’s easy, but what about:

22. 48 - x = 45
What is x?

23. 48 - x = 45
X = 3

24. 48 – x = 45
X = 3
Because 48 – 3 = 45

25. 100 + x = 125
What is x?

26. 100 + x = 125
X = 25

27. 100 + x = 125
X = 25
Because 100 + 25 = 125

28. X – 3 = 45
One way to find x is to substitute numbers until you
find the one that makes the equation true.
50 – 3 = 45
Is this true?
This is an equation

29. No because
50 – 3 = 47
It must equal 45

30. 49 – 3 = 45
Is this true?

31. No because
49 – 3 = 46
It must equal 45

32. 48 – 3 = 45
Is this true?

33. Yes! because
48 – 3 = 45
When you try “plugging” in different
numbers for x, it’s called substitution.

34. Review
x - 3 = 45
X ≠ 50 X = 48X ≠ 49
This (≠) means “not equal”

35. Review
x - 3 = 45
X ≠ 50 X = 48X ≠ 49
This (=) means “is equal”

36. For
x + 10 = 15
Which is true?
X ≠ 4
X = 4
X = 25

37. For
x + 10 = 15
Which is true?
X ≠ 4
X = 4
X = 25

38. For
x + 10 = 15
Which is true?
X ≠ 4
X = 4
X = 25

39. When you find the right number for
x, the problem is solved and the
equation is true!
A couple more, and your done!

40. 322 - x = 222
Solve for x?

41. 322 – x = 222
X = 100

42. X = 100
Because 322 - 100 = 222
322 – x = 222

43. 100 ÷ b = 25
Solve for b?

44. 100 ÷ b = 25
Solve for b?
Sometimes other letters are
used besides x, but mostly x
is used.

45. 100 ÷ b = 25
b = 4

46. b = 4
Because 100 ÷ 4 = 25
100 ÷ b = 25

47. 322 – x = 222
X = 100

48. X = 100
Because 322 - 100 = 222
322 – x = 222

49. 10 =
𝑥
2
Solve for x?

50. 10 =
𝑥
2
X = 20

51. 10 =
𝑥
2
X = 20
Because 10 =
20
2

52. Algebra is all about solving
for an unknown like x
Al-Khwarzmi - who founded the discipline of al-jabr