Rules of exponents and the distributive property apply.
(x+y)² = (x+y)·(x+y) . . . . . meaning of exponent of 2
= x·(x+y) +y·(x+y) . . . . . . . distributive property
= x·x +x·y +y·x +y·y . . . . . distributive property
= x² +x·y +x·y +y² . . . . . . meaning of exponent of 2, commutative property of multiplication
= x² +(1+1)·x·y +y² . . . . . . distributive property
= x²+2xy+y² . . . . . . . . . the desired form
Thus
(x+y)² = x²+2xy+y²
The right answer is A as the angle would be X to the power of 2 indicating A
Answer:
I am pretty sure it's −2.7710843373
Order doesn't mater so use combinations:
6C3 = 6!/ (3! (6-3)! ) = 6! /(3!*3!) = 6*5*4*3! / (3! 3!) = 6*5*4/3*2*1) = 20
