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  • Created by: kaci12345
  • Created on: 02-03-18 13:15

collecting like terms

In algebra you use letters for unknown numbers. 

You can simplify expressions that contain + and - by collecting terms. example: h+h+h=3h

A more harder expession to simplify would be: 2p+3q-5p = 2p-5p+3q+q    = -3p + 4q. - this is in its simpliest form. 

You could get some exam questions like:

6n + n - 4n. This would simplify to 3n.

Another exam question could be finishing the sentence like this:

Root   formula   factor   term 

Choose a word from the list above to make this sentence correct. 

8x is a            in 3y + 8x + 5. The corret answer would be term.

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simplyfying expressions

You need to be able to simplify expressions that contain x or /. These rules will help. 

1) multiplying expressions - multiply any number part first. Then mulitply the letters. 

2) dividing expressions - Write the division as a fraction. Cancel any number part. If the same letter appears on the top and bottom you can cancel that aswell. 

Some exam questions you could get are: 8y/4 = 2y - You would put this in a fractions before you get your answer. 

Another exam question would be: 10pq/2p = 5q - This is because you have to divide the numbers first and then cancel out and letters that are the same and the number you get you put the remainding letter on the end to make the answer. 

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substitution

If you know the values of the letters values of the letters in an algebraic expression, you can substitute them into the expression. This lets you work out the value of the expression.

X = 7 and Y = 2. These values have been substituted back into this equation: x + 5y . 

5y - 5 x y. Substitute 2 in and this becomes 5 x 2 = 10.

x = 7

10 + 7 = 17

An exam question could be: work out the value of this expression using X as 3 and Z as 10 

x + z 

X = 3 Z = 10

3 + 10 = 13

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