What does the word Algebra actually mean Algebra
What does the word ‘Algebra’ actually mean? Algebra is when we use a letter to represent ( stand for ) a value or number But why use a letter when we can use a number? Unfortunately, we can’t always put a number or value to an amount so that’s when we use letters or Algebra
12 eggs in this box. . There are ____ We don’t need algebra we can use a number !!
There are ____ smarties We don’t know how much. . We need a letter to hold the number we don’t know!!
• Important Points… Points
Important Points… Points •
Collecting Like Terms KEYWORD : SIMPLIFY = 3 y = 5 b = 3 a + 2 b = 3 g – 5 n = 6 y + 4 t
Example •
• Simplify these expressions = COLLECT LIKE TERMS
LIKE & UNLIKE TERMS • b & b are LIKE terms • a & b are UNLIKE terms • Terms which use different powers are not like terms • z and z 2 are not like terms. They cannot be collected together!
Mini - whiteboards SUBSTITUTION: What is the value of y? y = 3 r - 10 when r = 3 y = 3 c – 5 when c = -1 y = f 2 + 7 when f = 5 y = 7 x when x = 10 y = 12 w + 12 when w = 6 y=a– 4 when a = -2 B –+ 8 b whenb. B==73 yy==13 when y = 8 ty+=11 2 Q – 9 when t=4 Q=8
Algebra: expressions • Writing Expressions • Simplifying expressions by collecting like terms • Substituting numbers instead of letters in expressions
Algebra Revision QUIZ Have I understood my basic algebra?
Sam thinks of a number and doubles it, the answer is: •
• Kyra thinks of a number, multiplies it by 3, then adds 2, the new number is:
Find the value of 2 y+7 when y=4 •
Find the value of 3 a-2 b when a=-1 and b=2 •
24. Find the value of z-2 y when z=8 and b=-2 •
A+2= 2 2 6 A =4
A+2=6 A + 2 – 2 = 6– 2 A+2– 2=6– 2 A=4
C+3=8 C + 3 – 3 = 8– 3 C+3– 3=8– 3 C=5
÷ 3 3 x = 12 x = 4
2 B = 6 2 ÷ = ÷ 2 B 2 6 B=3
3 D = 12 ÷ 3 D = 12÷ 3 3 D=4
3 H = 9 ÷ 3 H = 9÷ 3 3 H=3
2 J = 2 ÷ = 2 J ÷ 2 2 2 J=1
-1 -1 2 x + 1 = 5 ÷ 2 2 x = 4 x = 2
2 E + 3 = 7 Our aim is to get E on its own So first we get rid of the 3 2 E + 3 -3 = 7 -3 2 E = 4 Then we get rid of the 2 ÷ 2 E 2 ÷ 42 = E=2
4 c 5 = 11 Our aim is to get c on its own So first we get rid of the -5 4 c - 5 + 5= 4 c = 16 + 11 5 Then we get rid of the 4 4 c ÷ 4 ÷ 164 = c=4
4 k + 2 = 10 Our aim is to get k on its own So first we get rid of the +2 4 k +2 - 2= 10 - 2 4 k = 8 Then we get rid of the 4 ÷ 4 k 4 =8 k=2 ÷ 4
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