Answer: Correct two digit number= 24
Step-by-step explanation:
Let
x= tens digit (wrong one)
and y= zeroes digit
and z= tens digit (right one)
Now according to the statement,
(10x+y)² - (10z+y)² = 2340
Simplifying this we get
(x-z)(5x+y+5z)= 117= 1 * 3 * 3 * 13
So it could either be
x-z=1 or x-z=3
If we take the x-z=1
then 5x+y+5z=117
which is not possible as maximum value we can get from this is 99.
This leaves us with x-z=3
so 5x+y+5z= 39
Put x=3+z
We get,
y+10z= 24
Now as y and z both are single digits so the only possible numbers to fit these are y=4 and z=2.
Put z=2 in x=3+z , we get x=5
So the numbers become 10x+y= 54
and 10z+y= 24
Their sum is 54+24=78
Check
54²-24²= 2340 so it is correct.
First question:
4(3x-5) + (2x -2)(4 + 3x-5)
Simplify -----> 12x - 20 + (2x-2)(3x-1)
Multiply the second part -----> 12x - 20 + 6x^2 -8x + 2
Combine like terms --------> 6x^2 + 4x - 18
Each side of the addition sign represents one of the rectangles above which is then added to get the area of the entire figure.
Second question:
The average is the summation of each data value divided by the number of data values. So it would be
(4 + 5 + 9)/ 3
Simplify ------> 18/3
Divide --------> 6
It is not linear because x is raised to the second power. Therefore it is not straight and would be kindof like a rainbow cut in half on the graph..
