3a - 4b = 21
check (-2 , -3)
3(-2) -4(-3) =21
-6 +12 = 21
6 does not = 21 so NO
check (0 , 7)
3(0) -4(7) =21
0-28=21
-28 does not equal 21 so NO
check (-3 , -2)
3(-3) -4(-2) =21
-9 +8 = 21
1 does not = 21 so NO
check (7 , 0)
3(7) -4(0) =21
21 = 21
Choice D
The first thing we must do for this case is to define variables.
We have then:
P: pressure
A: Area of the sole of the shoe
Since the variation is inverse, we have an equation of the form:

We must find the value of k.
For this, we use the following data:
when the shoes have a sole area of 40 in ^ 2 The pressure is 4 lbs / in ^ 2
Substituting values we have:

From here, let's clear k:

Then, the equation is:
Answer:
The equation that relates these variables is:
Answer:
4 and 40
Step-by-step explanation:
2/5 of 10 is 4
2/5 of 100 is 40
Answer:
$20.60
Step-by-step explanation:
Price before discount = $21
Discount rate = 10% or 0.1
Discount in dollars = 0.1* 21 = $2.1
Price after discount = $21 -$2.1 = <em>$18.90</em>
If sales tax is 9% or 0.09
amount of tax will be = 0.09 * 18.90 = <em>$1.701</em>
Total price of the phone including taxes = Price before tax + tax amount;
Total price = 18.90 +1.701
= 20.601
Therefore total price will be $20.60