Parallel lines have the same gradient.
If in doubt FACTORISE or use PYTHAGORAS
Before solving a quadratic equation make it equal to zero
If a question requires you to solve, but doesn't give an equation, use your initiative
Call whatever you start with x and work from there
Suitable degree of accuracy means
To the same accuracy as quantities in the question
to 3 significant figures
Don't round until the end of a question.
Try to use full answers throughout your calculations, then round appropriately at the end.
To solve a quadratic equation, use the following methods in order of preference.
Use the quadratic formula
Complete the square
Before trying to solve, get it equal to zero.
Cancel if you can
FACTORISE if you can
Always, when making something the subject, make sure you have it alone on one side only.
To do this, make sure you start with the intention of getting everything with your subject in together.
Never use factorisation or quadratic formula to solve until what you want to solve equals zero.
If using quadratic formula beware of negatives
IDENTITY - 3 lines
EXPRESSION - no equality sign
FORMULA - more than one unknown, would need information about at least one variable to find others
EQUATION - one unknown that can be solved
See a bracket - deal with it first!
Solve inequalities like equations but remember the sign at the end.
Only change sign if multiplying/dividing by a negative.
When working with algebra use brackets to stop silly mistakes
Always FACTORISE or cancel when you can