Lesson 9 - 11 Review

A botanist who works with endangered species tracks the growth of a sequoia tree. The botanist records the tree's height each year. What is the equation of the line in slope-intercept form?

What is the y-intercept of the line represented by the equation?

-0.4x + 0.05y - 1.25 = 0

(HINT: rewrite the equation in slope-intercept form)

• -1.25

• 0.05

• 8

• 25

Tomás makes leather lanyards to sell. He charges a base fee and a cost per inch of the finished lanyard. The line shows the cost, y, for x inches of lanyard. Write an equation for the line in slope-intercept form.

Demarco has some money saved, and he wants to save more. He decides to save the same amount every month. The linear equation 10y - 200x = 500 can be used to find y, the amount of money Demarco has saved after x months. Demarco makes a graph of this equation. Tell whether each statement about Demarco's graph is True or False. (HINT: write the equation in slope-intercept form)

Groups:

(a) True

,

(b) False

• The point (0, 500) is on the line.

• The slope is 20.

• The y-intercept is 50.

• The line slants downward from left to right.

• The slope is -200.

Challenge: What is the y-intercept of a line that passes through the points (2, 7) and (6, 1)?

Write your answer as an ordered pair.

What is the solution to the equation?

What is the value of k?

Mr. McClary writes the equation 3(3x - 10) = 5(x + 10). The equation shows the relationship between the perimeter of an equilateral triangle and the perimeter of a regular pentagon. What is the perimeter of the pentagon?

• 20

• 50

• 100

• 150

How many solutions does the equation have?​ (a)  

• one solution
• no solution
• infinite solutions

How many solutions does the equation have?​ ​ ​ (a)  

• no solution
• infinite solutions
• one solution