Year 9 Yearlyz Flashcards
(53 cards)
How do you factorise an algebraic expression
- Find the HCF of the terms and write it outside the brackets
- divide each term by the HCF and write the answers inside the brackets
- To check that it’s correct expand it.
How to expand the difference of 2 squares
The rule is =
(a+b)(a-b) = a2 - b2
The answer is always a minus
What is commission
Commission is earned by sales people. It is calculated as a percentage of the value of items sold or income made.
How do you find the unknown angle
Shift tan 35 ab/c =
How to Find the surface area of a closed cylinder
2 x Pie x radius2 + 2 x pie x radius x height
How do we find the exterior angle of a triangle
It is equal to the sum of the two interior opposite angles
Triangle interior angle + triangle interior angle = triangle exterior angle
How do you find the net pay
Net pay= gross pay - tax - other deductions
How to expand a perfect square
(A + b)2 = a2 + 2ab + b2
E.g (m + 9)2
= m2 + 81m + 92
The 2 at the end are meant to be squared 2
What is continuous data
This can be any time of data such as 42.36263 degrees celcius
What is the sin
Opposite/hypotenuse
Look at the fat index laws in your photos
Ye
What is the median
The middle score
How to find the percentage profit
Profit/Cost Price X 100%
What is discrete data
Legit just whole numbers
Look at chapter 4 and learn
Yet
What is numerical data
Data that can be counted
Study CHAPTER 7
Do it
How to add or subtract algebraic fractions
To add or subtract factions, convert them (if needed) so that they have the same denominator, then simply add or subtract the numerators.
How to test for a Pythagorean triad
- square all numbers
- plus the first 2 numbers
- if it equals the third one it is a Pythagoras triad
What is categorical data
These can be put into categories such as someone’s hair colour
What is the units of = Kgs to grams Hours to seconds Kilometres to metres Hours to minutes Days to hours Litres to mL
1kg = 1000 g 1h = 3600 s 1km = 1000m 1hr = 60 min 1d = 24 hrs 1L = 1000mL
How many minutes is 1 degree
1 degree = 60’
How to find the surface area
Find the area of each face and add the areas together
Make sure to square the answer at the end
How to factorise a quadratic trinomial E.g x2 + 6x + 8
E.g x2 + 6x + 8
=(x+__)(x+__)
=(x+2)(x+4)
This is because 2 + 4 is 6 and 2 x 4 is 8
You can find this by dividing 8 by 2,3,4 and then plusing the 2 to whatever you got or 3 to whatever you got.
