In this unit we learnt some patterns.
From this example, If we use the ordinary method to solve this question must be use FOIL, that need to do lots of works, so we need a easier way t solve this question. In this diagram, we could find out the two parts that I circled are the same just different signs, so they cancelled out. What left? The x square and the number. So the first Pattern that we need to remember is
When we do the questions like this example next time, we could use this pattern to solve questions faster.
This is the second Pattern.
In this picture we can see there are two “2x”, is 4x just like 2 times 2 times x. So we could figure out a pattern to help us solves this type of questions faster.
Hint: (a-b)^2 is similar way to solve.
This is the third Pattern, I showed some examples in this picture. From these examples we could find out a pattern is:
When we got this pattern, we do some questions like x^2+8x +15 next time, we could easily solve it.