SLOPE WORD PROBLEMS
SLOPE WORD PROBLEMS

Lesson Objective: 4.01a

Students will know how to solve word problems
using slope
SLOPE WORD PROBLEMS

In 2005, Joe planted a tree that was 3 feet tall.
In 2010, the tree was 13 feet tall. Assuming
the growth of the tree is linear, what was the
rate of growth of the tree?
SLOPE WORD PROBLEMS

In 2005, Joe planted a tree that was 3 feet tall.
In 2010, the tree was 13 feet tall. Assuming
the growth of the tree is linear, what was the
rate of growth of the tree?
What does “rate of growth” mean?
 Slope!

SLOPE WORD PROBLEMS

Remember the slope equation:

In order to find the slope we need two points
SLOPE WORD PROBLEMS

In 2005, Joe planted a tree that was 3 feet tall.
In 2010, the tree was 13 feet tall. Assuming
the growth of the tree is linear, what was the
rate of growth of the tree?

Remember, x is always years, so replace x2 with
the second year and x1 with the first
SLOPE WORD PROBLEMS

In 2005, Joe planted a tree that was 3 feet tall.
In 2010, the tree was 13 feet tall. Assuming
the growth of the tree is linear, what was the
rate of growth of the tree?

Replace y2 with the height from the second year
and y1 with the first
SLOPE WORD PROBLEMS
Simplify the top
 Simplify the bottom
 Simplify the fraction to get m. Keep it as a
fraction if it can’t be simplified

SLOPE WORD PROBLEMS

In 2005, Joe planted a tree that was 3 feet tall.
In 2010, the tree was 13 feet tall. Assuming
the growth of the tree is linear, what was the
rate of growth of the tree?

The slope is 2, so the tree grows 2 feet per year
SLOPE WORD PROBLEMS

In 1995 a public library had 16,000 books on
its shelves. In 1999 the library had 19,000
books. Assuming a linear increase, how many
books were added to the library each year?
SLOPE WORD PROBLEMS

In 1995 a public library had 16,000 books on
its shelves. In 1999 the library had 19,000
books. Assuming a linear increase, how many
books were added to the library each year?

We’re looking for how many for each year,
usually the word “each” means slope.
SLOPE WORD PROBLEMS

In 1995 a public library had 16,000 books on
its shelves. In 1999 the library had 19,000
books. Assuming a linear increase, how many
books were added to the library each year?
Years are always x so replace the x’s with the
years
 Replace the y’s with the number of books for
each year

SLOPE WORD PROBLEMS
Replace y2 with 19000 and y1 with 16000
 Replace x2 with 1999 and x1 with 1995
 Simplify the top and the bottom
 Reduce the fraction

SLOPE WORD PROBLEMS

In 1995 a public library had 16,000 books on
its shelves. In 1999 the library had 19,000
books. Assuming a linear increase, how many
books were added to the library each year?

m = 750, therefore the library adds 750 books
each year
SLOPE WORD PROBLEMS

Monica feeds her dog the same amount of dog
food each day from a very large bag. ON the 3rd
day, she has 44 cups left in the bag, and on the
11th day she has 28 cups left. How many cups
of food does she feed her dog a day?
SLOPE WORD PROBLEMS

Wendy bought a car for $25,000 and its value
depreciated linearly. After 3 years the value
was $21,250. What was the amount of yearly
depreciation?
SLOPE WORD PROBLEMS

Jamal’s parents give him $20 to spend at
camp. Jamal spends the same amount of
money on snacks each day. After 4 days he
has $12 left. How much money is he spending
each day?