solving equations: the woodchuck
TRANSCRIPT
How much wood would a woodchuck chuck if a woodchuck could chuck wood?
This woodchuck can chuck 3/4 of a cord of wood per hour.
He has chucked 20 cords of wood total. How many hours was he chucking?
Write this as an equation where x is the number of hours.
3
4x = 20
Solve the equation for x.
3
4x = 20
4
3· Multiplication principle
4
3·
X = 26 hours803 hours =
23
Same woodchuck, different wood pile.
Another woodhcuck has kindly donated 7 cords of wood to start our friend off.
He can still chuck at 3/4 cord per hour.
How many hours will it take our friend to chuck the same 20 cords?
Write this as an equation where x is the number of hours.
3
4x = 20+ 7
Solve the equation for x.
3
4x = 20+ 7
Addition principle
4x = 20 - 7+ 7 - 73
4x = 1334
3· · 4
3Multiplication principle
x = 523
hours = 12.33 hours
Our woodchuck friend is very busy! How
many hours would it take him to chuck 20
cords of wood if he started off with 2
cord of wood?
78
Write this as an equation where x is the number of hours.
Solve the equation for x.
Use the Addition principle
Use the Multiplication principle
Rewrite the equation
Write the solution
Our woodchuck friend is very busy! How
many hours would it take him to chuck 20
cords of wood if he started off with 2
cord of wood?
78
Write this as an equation where x is the number of hours.
Solve the equation for x.
Use the Addition principle
Use the Multiplication principle
Rewrite the equation
Write the solution
Solution
34
x + 238
= 20
34
x + 238
= 20
34
x + 238
= 20238
- - 238
34
x = 1378
43 ·
43·
x = 54824 = 28.83 hours