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
19) 15/a = 3/2
Start by cross multiplying....
3a = 30
Divide both sides 3
a = 10
21) 2/7 = 4/d
2d = 28
d= 14
23) 8/p = 3/10
80 = 3p
p = 26.66
25) 2 / -5 = 6/t
2t = -30
t = -15
I believe 3m 7cm 3cm= 13 meters :).
Answer:
Step-by-step explanation:
Answer:
number 2 or 4 but i think 2
Step-by-step explanation:
