Answer:
1. distance = sqrt( (7-7)^2+(2- -8)^2) = 10
2. check out desk (0,0 ) => distance = sqrt( (0- -9)^2+(0-0)^2) = 9
3. last corner ( -3, 4)
4. area = sqrt( (-10- -10)^2+(10-4)^2) x sqrt( (-3- -10)^2+(10-10)^2) = 6x7 =42
5. check desk (0,0), south direction = negative y axis => P_beginning (0,-20), P_end (0,-(20+25)) = (0,-45)
6. A(-2,-1) and B(4,-1) lie in y =-1. AB = sqrt( (-2- 4)^2+(-1- -1)^2) =6
=> area = 3.6x6 =21.6
=> peri = 2x(3.6+6) = 19.2
7. A(-5,4) and B(2,4), AB = sqrt( (-5- 2)^2+(4- -4)^2) = 7 => AB is base
=> p = peri = 7+ 8.3x2 = 23.6
=> area = sqrt[px(p-7)x(p-8.3)x(p-8.3)]
=sqrt[23.6x(23.6-7)x(23.6-8.3)x(23.6-8.3)] = 302.8
Let's say "n" is a natural number. {1,2,3,4,..} To ensure we have an even number we will multiply "n" by 2. Two times any number will make an even number.
consecutive even numbers are like; 2, 4, 6, 8, 10 .. etc. Add +2 to the previous number to get the next consecutive.
1st even number = 2n
2nd even number = 2n + 2
3rd even number = 2n + 4
twice the first number (2n) is 20 more then the second (2n + 2).
2(2n) = 2n + 2 + 20
4n = 2n + 22
4n - 2n = 22
2n = 22
n = 11
Now use n = 11 to find the 3 consecutive even numbers.
1st even number = 2(11) = 22
2nd even number = 2(11) + 2 = 24
3rd even number = 2(11) + 4 = 26
22, 24, 26
Simple...
you have:
1.) -8x-16 --->>>
Factor out a -8 -->>
-8(x+2)
2.)9d+15db --->
Factor out 3d -->
3d(3+5b)
3.) 2a-9ax-->>
Factor out -a -->
-1a(9x-2)
Thus, your answer.