Algebra

Question 1

What is factorising

Answer 1

Reverse of expanding, putting the brackets in.

Question 2

What order do you need to think through when factorising

Answer 2

1.Look for common factors in all terms,if there is they come before the bracket and work out what needs to go in the bracket so when you multiply it out it will be what you started with.
2.look for so,something squared,minus something squared, this is called difference of two squares, answer is two brackets which are the same apart from one is a plus, one is a minus. E.G-x^2-y^2=(x+y)
(x-y)
If its neither of the above the answer will be two brackets times together

Question 3

How do you factorise into two brackets(where there is a single x

Answer 3

X^2+bx+c
Look for two numbers that multiply to make ‘c’ and add to make ‘b’
It is nest to think about the signs first
If both terms are positive the both brackets will be positive
If the last term is positive but second term is negative the brackets will both be negatives.
If the last term is negative there is one positive and one negative in the brackets.

Question 4

How do you solve a quadratic

Answer 4

There are free possible methods,1-factorise
2-quadratic formula
3-completing the square

Question 5

How do you solve a quadratic by factorising

Answer 5

Make sure all the terms are on one side of the equals and the other side is 0,if not rearrange.
Factorise the algebra expression into one or two brackets
Now you have two things that multiply to make 0,this can only happen if one of them =0
Substitute the answer(s) into the original equation to checkit works