Answer:
The answer is A. 5 notebooks and 13 pencils
Step-by-step explanation:
1. Identify your x and y variables.
x - number of notebooks
y - number of pencils
2. Set up two equations to come up with a system of linear equations.
x + y = 18
2.3x + 1.25y = 27.75
3. In order to solve for one of the variables (either x or y), multiply the first equation with the additive inverse (when added together, the answer is zero; one number will be positive while the other number will be negative) of the coefficient of either x or y, so you can eliminate that variable. In this case, I choose the coefficient of y which is 1.25. So, the first equation will look like this:
-1.25(x + y) = 18
-1.25x - 1.25y = -22.50
4. Next, eliminate the y variable and solve for x.
-1.25x - 1.25y = -22.50
2.3 x + 1.25 y = 27.75
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<u>1.05</u> x = <u>5.25</u>
1.05 1.05
x = 5 Joanna bought 5 notebooks.
5. Then, solve for y.
5 + y = 18
y = 18 - 5
y = 13 Joanna bought 13 pencils.
If you want to check your work, just plug in 5 and 13 into one of the two original equations. Simplify the equations, and you should get a true statement.
5 + 13 = 18
18 = 18
Step-by-step explanation:
<em>Given</em>
<em>points </em><em>(</em><em> </em><em>4</em><em> </em><em>,</em><em>5</em><em> </em><em>)</em><em> </em><em>and </em><em>(</em><em> </em><em>6</em><em> </em><em>,</em><em> </em><em>2</em><em>)</em>
<em>Slope </em><em>(</em><em>m) </em>
<em>=</em><em> </em><em>(</em><em> </em><em>y2 </em><em>-</em><em> </em><em>y1</em><em>) </em><em>/</em><em> </em><em>(</em><em> </em><em>x2 </em><em>-</em><em> </em><em>x1</em><em>)</em>
<em>=</em><em> </em><em>(</em><em> </em><em>5</em><em>-</em><em>2</em><em>)</em><em>/</em><em>(</em><em>4</em><em>-</em><em>6</em><em>)</em>
<em>=</em><em>3</em><em>/</em><em>-</em><em>2</em>
<em>=</em><em> </em><em>-</em><em>3</em><em>/</em><em>2</em>
Answer:
b........................................
Step-by-step explanation:
Tenths value should be 6, and hundreds value should be 4.
The tenths digit it the first number to the right of the decimal, while the hundreds digit is the third number to the left of the decimal.
Answer:
P(B) = 0.20
Step-by-step explanation:
For these events, which are not independent or mutually exclusive, the relation between the various probabilities is ...
P(A or B) = P(A) +P(B) -P(A and B)
Solving for P(B), we find ...
P(B) = P(A or B) +P(A and B) -P(A)
P(B) = 0.77 +0.13 -0.7 = 0.20
The probability of B is 0.20.
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<em>Additional comment</em>
The formula applies to independent and mutually exclusive events, as well. For independent events, P(A and B) = P(A)·P(B). For mutually exclusive events, P(A and B) = 0.
