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Objective: Students will be able to solve consecutive integers problems. Consecutive Integers. Linear Problems. Two Cases for Consecutive Numbers. Case one: Consecutive numbers like 4, 5, 6,7, … x, x + 1, x + 2, x + 3, … Case Two: Consecutive odd numbers like –5, –3, –1, 1, 3, …
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Objective: Students will be able to solve consecutive integers problems. Consecutive Integers Linear Problems
Two Cases for Consecutive Numbers • Case one: • Consecutive numbers like 4, 5, 6,7, … • x, x + 1, x + 2, x + 3, … • Case Two: • Consecutive odd numbers like –5, –3, –1, 1, 3, … • x, x + 2, x + 4, x + 6, … • Consecutive even numbers like –4, –2, 0, 2, 4, … • x, x + 2, x + 4, x + 6, …
Read and solve • The sum of two consecutive even numbers is -14. What are the two numbers.
Step 1: • Define the unknown. • Let x = 1st consecutive number. • Let x + 2 = 2nd consecutive number.
Step 2: • Setup the Equation. • (x) + (x + 2) = -14
Step 3: • Solve the equation. (x) + (x + 2) = -14 x + x + 2 = -14 2x + 2 = - 14 - 2 - 2 2x = -16 2 2 x = - 8
Step 4 • Answer the question x = –8 x + 2 = • Check –8 + (–6) = –14 -6
Speed, Distance & Time Speed, Distance, Time Calculations
The aim of this lesson is to be able to use the correct formulas to calculate speed, distance or time
Reminder: How to change minutes into a decimal 15 mins = 0•25 hour So: 3 hours 15 mins = 3•25hours 30 mins = 0•5 hour So: 7 hours 30 mins = 7•5hours 45 mins = 0•75 hour So: 2 hours 45 mins = 2•75hours
Distance Distance = Speed x Time Speed = Time Distance Time = Speed D S T The 3 formulas for Speed, Time & Distance: Solving for Speed Solving for Time Solving for Distance Remember them from this triangle:
Distance Time 28 = 1•75 D S T A windsurfer travelled 28 km in 1 hour 45 mins. Calculate his speed. Speed = 1 hour 45 mins = 16 km/h Answer: His speed was 16 km / hour
D S T A salesman travelled at an average speed of 50 km/h for 2 hours 30 mins. How far did he travel? Distance = Speed x Time = 50 x 2•5 2 hour 30 mins = 125 km Answer: He travelled 125 km
Distance Speed 555 = 60 D S T A train travelled 555 miles at an average speed of 60 mph. How long did the journey take? Time = = 9•25 hours = 9 hours 15 mins Answer: It took 9 hours 15 minutes