Answer:
Cost of one pencil: 
Cost of one eraser: 
Step-by-step explanation:
Let be "p" the cost in dollars of one pencil and "e" the cost in dollars of one eraser.
Based on the information given in the exercise, you can set up the following system of equations:

You can use the Elimination Method to solve the system of equations.
Multiply the first equation by -3 ad the second one by 4. Then add the equations and solve for "e":
{
Substitute the value of "e" into any original equation and solve for "p":

The answer is D.
You have to make the whole numbers equal to then solve for the exponents:
F(x) means y, therefore, y is 9.
9 = 3^x.
3^2 is the same as 9.
Then, 3^2 = 3^x.
Then solve for the exponents,
2 = x
Therefore your answer is 2.
0.4% can be written as 0.004 in decimal.
Step-by-step explanation:
Let the total amount she wants to save be 'a'
Starting amount = 0.4% of the total amount
= 0.4% of a
= (0.4/100) a
0.4% = 0.4/100
= 0.004
0.4% can be written as 0.004 in decimal.
Answer:
r = 1.9
Step-by-step explanation:
7r + 7 = 20.3
<u> - 7 - 7 </u>
7r = 13.3
divide by 7
r = 1.9
Answer:

Step-by-step explanation:
Given


Required
Eliminate a
Multiply the first equation by -4

Add to the second equation

Solve brackets

Open bracket


At this point, a has been eliminated;
From the list of given options, the option that answers the question is 