Question

The graph below shows how much money you have in savings each week. Use

this graph to answer questions (a – g).
a. According to the graph how much money did you start with in your savings?
b. How much money will you have after 5 weeks of saving?

Answer 1

Explanation:

a). Since starting point of the line is (0, 50),

Therefore, I started with the saving of $50.

b). Since endpoint of the segment is (5, 175),

Money with me after 5 weeks will be $175.

c). Let the equation of the line given in the graph is,

y - y' = m(x - x')

Where (x', y') is a point lying on the graph.

And 'm' is the slope of the line.

Slope of the line =
`(175-50)/(5-0)`

m =
`(125)/(5)`

m = 25

Since, the line passes through (0, 50),

y - 50 = 25(x - 0)

y = 25x + 50

y = 25x + 50

For x = 6,

y = 25×6 + 50 = 200

For x = 7,

y = 25×7 + 50 = 225

For x = 8,

y = 25×8 + 50 =250

d). For x = 10 weeks,

y = 25×10 + 50 = $300

e). For x = 15 weeks

y = 25×15 + 50 = $425

f). For x = 50 weeks,

y = 25×50 + 50 = $1300

g). Equation of the line is,

y = 25x + 50