# Pg 63-68. This is a skill testing question 6 x (3 + 2) – 10 ÷ 2 = ? Which answer is correct? 5 10 15 25.

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Pg 63-68

This is a skill testing question 6 x (3 + 2) – 10 ÷ 2 = ? Which answer is correct? 5 10 15 25

Order of Operations Hopefully you remember this: BEDMAS Brackets, Exponents, Divide, Multiply, Add, Subtract

B – Do the operations in brackets first E – Next, evaluate any exponents D M A S Then, divide and multiply in order from left to right Then, add and subtract in order from left to right

Why do we have to do this? We need order of operations so that everyone can get the same answer all the time!

Adding & Subtracting with powers 3 3 + 2 3 We simply evaluate the powers before adding 3 3 + 2 3 = (3)(3)(3) + (2)(2)(2) = 27 + 8 = 35

Adding & Subtracting with powers 3 - 2 3 We simply evaluate the powers before subtracting 3 - 2 3 = (3) - (2)(2)(2) = 3 - 8 = -5

Adding & Subtracting with powers (3 + 2) 3 We add first since that is in the brackets (3 +2) 3 = (5) 3 = (5)(5)(5) = 125

Are these equal? (3+2) 3 = 3 3 + 2 3

Multiplying & Dividing with Powers [2 x (-3) 3 – 6] 2 [2 x (-3)(-3)(-3) – 6] 2 [2 x (-27) – 6] 2 [-54 – 6] 2 [-60] 2 = (-60)(-60) = 3600

Multiplying & Dividing with Powers (18 2 + 5 0 ) 2 ÷ (-5) 3 =(324 + 1) 2 ÷ (-5) 3 =(325) 2 ÷ (-5) 3 =105625 ÷ (-125) = -845

Solving Problems Using Powers Lyn has a square swimming pool, 2m deep with side length 4m. The swimming pool is joined to a circular hot tub, 1m deep with diameter 2m. Lyn adds 690g of chlorine to the pool and hot tub each week. This expression represents how much chlorine is present per 1 m 3 of water: The suggested concentration of chlorine is 20g/m 3 of water. What is the concentration of chlorine in Lyns pool and hot tub? Is it close to the suggested concentration

What was the actual important info? This reps the concentration of chlorine In g/m 3 The suggested concentration is 20g/m 3 What is the concentration of her hot tub and pool?

Basically solve the equation When an equation looks like this, first solve the numerator, and then solve the denominator, then divide.

The suggested is 20g/m 3 so this is pretty close

Homework Time Page 66-68 #3acegi, 4aceg, 5aceg,7, 10bdf, 12, 14ac, 18, 20

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