The answer is A, first the question said parallel so it should have same gradient and the gradient of the equation is 2 So eliminate D and bring (3,1) in each of the last three equation, and you will find just A conformed
Joanna bought 7 notebooks and 14 pencils
Step-by-step explanation:
Step 1 :
Let x denote the number of notebooks and y denote the number of pencils Joanna bought.
Cost of one notebook = $ 2.30
Cost of one pencil = $1.42
Step 2 :
Total of notebooks and pencils bought = 21
=> x + y = 21 => y = 21-x
Total cost of notebooks and pencils = $35.98
=> 2.3x + 1.42y = 35.98
Substituting y = 21- x here , we have,
2.3x + 1.42 ( 21-x) = 35.98
2.3x + 29.82 - 1.42x = 35.98
0.88 x = 6.16
=> x = 7
y = 21-x = 21-7 = 14
Step 3 :
Answer :
Joanna bought 7 notebooks and 14 pencils
The histogram which represents the data set with the smallest standard deviation is: C. Squad 3.
<h3>What is a histogram?</h3>
A histogram can be defined as a type of chart that's used to graphically represent a set of data points into user-specified ranges, especially through the use of rectangular bars.
Basically, standard deviation is a statistical tool which can be used to determine the measure of spread for the data represented in a histogram, especially based on the frequency of the specified ranges.
In this scenario, the histogram which represents the data set with the smallest standard deviation is Squad 3 because it has the least frequency on the y-axis.
Read more on histogram here: brainly.com/question/21304143
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The factors of this expression would be (x+9)(x-2). You have to find two numbers that are factors of -18 that add up to 7. These numbers would be 9 and -2:
(9)x(-2)= -18
and 9 + (-2)= 7
Your answer is C) (x-2).
Call the notebooks x, and the pencils y.
<span>3x + 4y = $8.50 and 5x + 8y = $14.50 </span>
<span>Then just solve as simultaneous equations: </span>
<span>3x + 4y = $8.50 </span>
<span>5x + 8y = $14.50 </span>
<span>5(3x + 4y = 8.5) </span>
<span>3(5x + 8y = 14.5) </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 24y = 43.5 </span>
<span>Think: DASS (Different Add, Similar Subtract). 15x appears in both equations so subtract one equation from the other. Eassier to subtract (15x + 20y = 42.5) from (15x + 24y = 43.5) </span>
<span>(15x + 24y = 43.5) - (15x + 20y = 42.5) = (4y = 1) which means y = 0.25. </span>
<span>Then substitue into equation : </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 5 + 42.5 </span>
<span>15x = 42.5 - 5 = 37.5 </span>
<span>15x = 37.5 </span>
<span>x = 2.5 </span>
<span>15x + 24y = 43.5 </span>
<span>15(2.5) + 24(0.25) </span>
<span>37.5 + 6 = 43.5 </span>
<span>So x (notebooks) are 2.5 ($2.50) each and y (pencils) are 0.25 ($0.25) each.</span>
