NEW
by AuMihi Tapara
We are learning to:
solve algebra equations by finding the value of a letter
combine like terms using algebra equations
Success Criteria:
name the value of a letter to make our algebra equation correct
combine all like terms using algebra equations
What is the value of a?
a + 5 = 12
12 - a = 5
a + 5 = 12
12 - a = 5
We need to find which number we would use instead of a to make this equation correct.
5
6
7
8
If a = 7 then:
7 + 5 = 12
12 - 7 = 5
a x 5 = 25
25 ÷ 5 = a
10
15
20
a x 5 = 25
25 ÷ 5 = a
We need to find which number we would use instead of a to make this equation correct.
If a = 5 then:
5 x 5 = 25
25 ÷ 5 = 5
You may also see terms like this in algebra: 2a or 7a
When there is no equation symbol between the number and letter, you need to multiply.
2a = 10 or 2 x a = 10
Therefore a = 5
7a = 14 or 7 x a = 14
a = 2
8a = 32
2
4
12a = 36
3
It doesn't matter which letter is shown in an algebraic equation when you are finding the value.
If 2a = 10 then a = 5
If 2b = 10 then b = 5
If 2c = 10 then c = 5
If 2z = 10 then z = 5
The letters are there to represent an unknown number.
A like term in algebra is a value that is the same.
a is the same as a
b is the same as b
If I have 2a + 3a this means that I have 2 of the letter a plus 3 of the letter a. These are like terms as the letter is the same. Therefore I would have 5a in total.
If I have 2a + 3b, this would mean that I have 2 of the letter a and 3 of the letter b. These are different letters so I would not add them together.
Watch the following video:
https://youtu.be/CLWpkv6ccpA
6a + 3a =
6 + 3 + a
9a
a + a
a + a + a + a + a + a + a + a + a
2a + 6a + 5a =
8a
11a
13a
15a
2a + 3b + 5a =
7a + 3b
2a + 8b
10a
2a + 3b
6b + 3c + 2b + 5c + 4d
8b + 12d
8b + 8c + 4d
6b + 10c + 4d
20b
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