11 choose 7 is equal to 11 choose 4. 11*10*9*8/4/3/2=330.
Answer:
+ 1) is an even number.
Take any n ∈ N, then n is either even or odd.
• Suppose n is even ⇒ n = 2m for some m ⇒ n(n + 1) = 2m(n + 1) ⇒ n(n + 1) is even.
• Suppose n is odd ⇒ n+ 1 is even ⇒ n+ 1 = 2m for some m ⇒ n(n+ 1) = 2nm ⇒ n(n+ 1)
is even. QED
2. The sum of the first n natural num
Step-by-step explanation:
a>50A is greater than 50
a<50a<50
a≥50A is greater than or equal to 50
a≤50
We will be using the Point Slope formula which is 
The information we are given is that m = -4 and the point is (2,-5), so we can input it into the equation.

This simplifies into 
Then we can subtract 5 from each side to get the answer:

Answer:
B and C
Step-by-step explanation:
Answer:
both have equal sides and equal Angel's
the angels In a rectangle 4 sides
the angles in a trapezoid is 4 sides