12 because if you take 2 and add it to 10 you get 12
You have to use the Pythagorean theorem but there is a little twist here since a square has has equal sides. So:
x^2+x^2=8
2x^2=8
2/2x^2=8/2
x^2=4
√x^2=√4
x=2
The side of the square is 2.
So now the area of a square is:
Side×Side
2×2=4
The area of the square is 4 centimetres
1)
x+10<-7
bring 10 to the other side
x<-10-7
x<-17
2)
-3x-4>5
bring -4 to the other side
-3x>9
divide -3 at the other side, since it is negative it changes to less than
x<-3
Answer: 715 ( C )
Explanation:
C (13,4) = (13!)/(4!*9!)
So it can be done on the calculator by 13C4
13! = 13 x 12 x 11 x 10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1
4! = 4 x 3 x 2 x 1
9! = 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1
13 x 12 x 11 x 10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 / ( 4 x 3 x 2 x 1 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 )
6,227,020,800 / 8,709,120
=715
So the correct answer is C, 715