Respuesta :
Answer:
Part 1) The number of classes must be greater than 20
Part 2) see the explanation
Part 3) [tex]\$68.76[/tex]
Part 4) [tex]\$12\ per\ hour[/tex]
Part 5) The equation that can be used is [tex]27x=242.73[/tex] and the cost of one print is [tex]\$8.99[/tex]
Part 6) The number of classes must be greater than 30
Step-by-step explanation:
Part 1) we know that
The linear equation in slope intercept form is equal to
[tex]y=mx+b[/tex]
where
m is the slope or unit rate
b is the y-intercept or initial value
Let
y ----> the total cost
x ----> the number of classes
we have
Members
The slope is [tex]m=\$10\ per\ class[/tex]
The y-intercept is [tex]b=\$100[/tex]
so
[tex]y=10x+100[/tex] ----> equation A
Non-Members
The slope is [tex]m=\$15\ per\ class[/tex]
so
[tex]y=15x[/tex] ----> equation B
To find out how many classes would a member have to take to save money compared to taking classes as a non-member, solve the following inequality
[tex]10x+100 < 15x[/tex]
Solve for x
subtract 10 x both sides
[tex]100 < 15x-10x[/tex]
[tex]100 < 5x[/tex]
Divide by 5 both sides
[tex]20 < x[/tex]
Rewrite
[tex]x > 20[/tex]
therefore
The number of classes must be greater than 20
Part 2) we have
The sum of 8 and 3 times a number is 23.
Let
x ----> the number
Remember that
3 times a number is the same that multiply 3 by the number ----> 3x
so
The sum of 8 and 3 times a number is 23 is the same that
[tex]8+3x=23[/tex]
solve for x
subtract 8 both sides
[tex]3x=23-8[/tex]
[tex]3x=15[/tex]
Divide by 3 both sides
[tex]x=5[/tex]
Part 3) we know that
The linear equation in slope intercept form is equal to
[tex]y=mx+b[/tex]
where
m is the slope or unit rate
b is the y-intercept or initial value
Let
y ----> the total cost of renting a car for one day
x ----> the number of miles
we have
The slope is [tex]m=\$0.42\ per\ mile[/tex]
The y-intercept is [tex]b=\$36[/tex]
so
[tex]y=0.42x+36[/tex]
For x=78 miles
substitute in the linear equation and solve for y
[tex]y=0.42(78)+36[/tex]
[tex]y=\$68.76[/tex]
Part 4) Let
x ----> Alice's normal hourly rate
we know that
40 hours multiplied by her normal hourly rate plus 10 hours (50 h-40 h) multiplied by 1.5 times her normal hourly rate must be equal to $660
so
The linear equation that represent this situation is
[tex]40x+10(1.5x)=660[/tex]
solve for x
[tex]40x+15x=660[/tex]
[tex]55x=660[/tex]
Divide by 55 both sides
[tex]x=\$12\ per\ hour[/tex]
Part 5) Let
x ----> the cost of one print
we know that
The cost of one print multiplied by 27 prints must be equal to $242.73
so
The linear equation is equal to
[tex]27x=242.73[/tex]
solve for x
Divide by 27 both sides
[tex]x=\$8.99[/tex]
Part 6) we know that
The linear equation in slope intercept form is equal to
[tex]y=mx+b[/tex]
where
m is the slope or unit rate
b is the y-intercept or initial value
Let
y ----> the total cost
x ----> the number of classes
we have
Members
The slope is [tex]m=\$7\ per\ class[/tex]
The y-intercept is [tex]b=\$120[/tex]
so
[tex]y=7x+120[/tex] ----> equation A
Non-Members
The slope is [tex]m=\$11\ per\ class[/tex]
so
[tex]y=11x[/tex] ----> equation B
To find out how many classes would a member have to take to save money compared to taking classes as a non-member, solve the following inequality
[tex]7x+120 < 11x[/tex]
Solve for x
subtract 7x both sides
[tex]120 < 11x-7x[/tex]
[tex]120 < 4x[/tex]
Divide by 4 both sides
[tex]30 < x[/tex]
Rewrite
[tex]x > 30[/tex]
therefore
The number of classes must be greater than 30