D is correct because it is a tenth and it becomes a hundredth
Answer:

Step-by-step explanation:
<u><em>The complete question is</em></u>
A chef bought $17.01 worth of ribs and chicken. Ribs cost 1.89 per pound and chicken costs 0.90 per pound. The equation 0.90 +1.89r = 17.01 represents the relationship between the quantities in this situation.
Show that each of the following equations is equivalent to 0.9c + 1.89r = 17.01.
Then, explain when it might be helpful to write the equation in these forms.
a. c=18.9-2.1r. b. r= -10÷2c+9
we have that
The linear equation in standard form is

where
c is the pounds of chicken
r is the pounds of ribs
step 1
Solve the equation for c
That means ----> isolate the variable c
Subtract 1.89r both sides

Divide by 0.90 both sides

Simplify

step 2
Solve the equation for r
That means ----> isolate the variable r
Subtract 0.90c both sides

Divide by 1.89 both sides

Simplify

therefore
The equation
is equivalent
The equation is helpful, because if I want to know the number of pounds of chicken, I just need to substitute the number of pounds of ribs in the equation to get the result.
Answer:
Air travels 6,920 meters in 20 seconds.
Step-by-step explanation:
If in one second air travels 346 meters, and you want to find out how many meters air travels in 20 seconds, then just multiply 346 by 20.
Answer: 
Step-by-step explanation:
Given
Azmyne decided to study a total of 
She spent
on Friday and
on Saturday
Hours spent on Friday

Hours spent on Saturday

She must study for

Answer:
see the explanation
Step-by-step explanation:
Let
x ---> kilograms of cement needed
y ----> kilograms of sand needed
z ----> kilograms of gravel needed
we know that
----> 

Divide 480 by 8
----> scale factor
Multiply the scale factor by the ratio 
<em>Find out the kilograms of cement needed</em>

<em>Find out the kilograms of sand needed</em>

<em>Find out the kilograms of gravel needed</em>
