Math T3 prob cooked

Algebraic expression

numbers and letters mixed together WITHOUT an equal sign

Variable

A letter standing in for a number you don't know yet.

Equation

Two things set equal to each other. Like x − 3 = 8.

Left side / right side

The stuff before the equals sign and the stuff after. They're always equal in value.

Solving an equation

Figuring out what number the letter has to be.

Linear equation

A normal equation where the letters highest power is 1, so no 2x or 3× or 67x

Inverse operation

The move that undoes another move. Undo a plus with a minus. Undo a times with a divide.

Guess Check & Improve

Guessing the answer/variable and substituting it with the vafiable

Balance method

Whatever you do to one side of the equation, do it to the other meaning. Meaning if there is a + 7 = 37 do a + 7 - 7 and then 37 - 7, so you end up with a = 30

Equivalent equations

Two equations that look different but give you the same answer.

Like terms

Terms with the same letter that you can just add together. Like 3x + 2x = 5x.

Expanding brackets

Multiply the number outside by everything inside. Like 3(x + 4) = 3x + 12. (You multiplied x and 12 by 3)

Formula

A rule that connects a couple of things together. Like area = length × width.

Subject of an equation

Whatever's sitting by itself on the left side. In T = 4x + 1 T is the subject because its alone on the left ting verity

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Metric system

Started in France in the 1790s. The word "metric" just means "measure."

Metre

Officially defined using how far light travels in a tiny split second.

Converting units

Conversion	Operation	Example
mm ➡ cm	Divide by 10	50 mm = 5 cm
cm ➡ m	Divide by 100	250 cm = 2.5 m
m ➡ km	Divide by 1,000	4,000 m = 4 km
km ➡ m	Multiply by 1,000	3 km = 3,000 m
m ➡ cm	Multiply by 100	1.2 m = 120 cm
cm ➡ mm	Multiply by 10	8 cm = 80 mm

Perimeter

All the sides and everything added up. I MISS THAT KIND OF MISERYY THE KIND WHERE U WERE NICE TO MEEEEE

Diameter & radius

You use diameter and radius when calculating circumference or an arc. For diameter you do x/360 x pi x diameter and for radius you do x/360 × 2 x pi x radius

Chord & tangent

A chord is a line connecting two points on the circle. A tangent just grazes the circle at one spot

Sector & segment

A segment is the bit you get by cutting straight across with the chord line. A sector is the same but bounded by 2 radius or radii

Circumference

The distance around a circle. Work it out with 2πr or πd.

Pi (π)

A number that's roughly 3.14 and goes on forever without repeating. It's used to calculate circumference.

Arc length

An arc is a part of the circle. You work out what fraction of the whole circle it is then do that fraction/360 × 2 x pi x radius

Perimeter of a sector

The same as arc but you do + 2r at the end

Quarter circle & half circle perimeter

90 and 180 degrees

how to indexes

keep on dividing the number by the lowest prime number thats divisible e.g

96 ÷ 2 = 48

• 48 ÷ 2 = 24

• 24 ÷ 2 = 12

• 12 ÷ 2 = 6

• 6 ÷ 2 = 3

• 3 ÷ 3 = 1

• Answer: 2⁵ × 3

You are given that 3600 = 144 × 25. Express 3600 in index form.

• 144 = 2⁴ × 3²

• 25 = 5²

• Answer: 2⁴ × 3² × 5²