Answer:

Step-by-step explanation:
Given Equation:
Equation:1
Equation:2
Dividing Equation:2 by '3' both the sides:
or
Equation:3
Putting the vale of 'x' in Equation:1


Subtracting '3' both sides



Putting value of 'y' in Equation:3


The solution of the equations is :

My guess would be x = -30
Answer:
because it can be written in the <u>form</u><u> </u>of p/q
Where p and q are integers, and q is <u>not</u> equal to zero.
Answer:
Perimeter of the ΔDEF = 10.6 cm
Step-by-step explanation:
The given question is incomplete; here is the complete question with attachment enclosed with the answer.
D, E, and F are the midpoints of the sides AB, BC, and CA respectively. If AB = 8 cm, BC = 7.2 cm and AC = 6 cm, then find the perimeter of ΔDEF.
By the midpoint theorem of the triangle,
Since D, E, F are the midpoints of the sides AB, BC and CA respectively.
Therefore, DF ║ BC and 
FD = 
= 3.6
Similarly, 

FE = 4 cm
And 
DE = 
= 3 cm
Now perimeter of ΔDEF = DE + EF + FD
= 3 + 4+ 3.6
= 10.6 cm
Perimeter of the ΔDEF is 10.6 cm.
Answer:
a)
Mean = sum of all numbers in dataset / total number in dataset
Mean = 8130/15 = 542
Median:
The median is also the number that is halfway into the set.
For median, we need to sort the data and then find the middle number which in our case is 546. Below is the sorted data
486 516 523 523 529 534 538 546 548 551 552 558 566 574 586
Standard Deviation (SD). Here X represents dataset and N= count of numbers in data
As per the SD formula, which is Sqrt ( sum (X_i - Meanx(X))/(N-1))
SD= 25.082
2) Formula for coefficient of skewness using Pearson's method (using median) is,
SK = 3* ( Mean (X) - Median(X))/(Standard Deviation) = 3*(542-546)/25.082 = -0.325
3) coefficient of skewness using the software method is also same which is -0.325