Given:
Three numbers in an AP, all positive.
Sum is 21.
Sum of squares is 155.
Common difference is positive.
We do not know what x and y stand for. Will just solve for the three numbers in the AP.
Let m=middle number, then since sum=21, m=21/3=7
Let d=common difference.
Sum of squares
(7-d)^2+7^2+(7+d)^2=155
Expand left-hand side
3*7^2-2d^2=155
d^2=(155-147)/2=4
d=+2 or -2
=+2 (common difference is positive)
Therefore the three numbers of the AP are
{7-2,7,7+2}, or
{5,7,9}
I do believe it is -1 1/2 because I chose two points on the graph (0, 300) and (150, 200). To find slope you need to plug it into an equation, which in this case looks like, (150-0)/(200-300) which then goes to 150/-100, which then simplifies to 15/-10, and then it converts to -1 1/2.
To get you answer multiply the length and width twice. Then the length and height twice. Then the width and height twice. And add it all up.
7* 1.25= 8.75
7* 1.25= 8.75
7*6.5= 45.5
7*6.5= 45.5
6.5*1.25=8.125
6.5*1.25=8.125
Answer:
I didn't understand what you mean
