I think :
(-4) + (-4) = -8
or
(-2) + (-2) + (-2) + (-2) = -8
but i am not sure
The answer to waht you are looking for is: x-y=-2
You subtract the 2 given sides from the perimeter so its
7a - 11b - (2a + b) - (a - 9b) ( Note the 2 sides must be in parantheses)
= 7a - 11b - 2a - b - a + 9b
adding like terms:-
= 4a - 3b
The answer is C. 4√5
To calculate this, we must find the greatest common divisor of these 3 numbers √20,√45, and √5.
The greatest common divisor is √5:
![\sqrt{20} = \sqrt{5*4} = \sqrt{5} * \sqrt{4} = \sqrt{5} *2= 2\sqrt{5}](https://tex.z-dn.net/?f=%20%5Csqrt%7B20%7D%20%3D%20%5Csqrt%7B5%2A4%7D%20%3D%20%5Csqrt%7B5%7D%20%2A%20%5Csqrt%7B4%7D%20%3D%20%5Csqrt%7B5%7D%20%2A2%3D%202%5Csqrt%7B5%7D)
![\sqrt{45} = \sqrt{5*9} = \sqrt{5} * \sqrt{9}=\sqrt{5}*3 = 3\sqrt{5}](https://tex.z-dn.net/?f=%20%5Csqrt%7B45%7D%20%3D%20%5Csqrt%7B5%2A9%7D%20%3D%20%5Csqrt%7B5%7D%20%2A%20%5Csqrt%7B9%7D%3D%5Csqrt%7B5%7D%2A3%20%3D%203%5Csqrt%7B5%7D%20)
Therefore,