The answer is a vertex. Corners of any shape are vertexes
Answer:
(-1, 5/2)
Step-by-step explanation:
That is what I got
Answer:
D
Step-by-step explanation:
I’m not sure but none of the others made sense
Answer:
a) 1+2+3+4+...+396+397+398+399=79800
b) 1+2+3+4+...+546+547+548+549=150975
c) 2+4+6+8+...+72+74+76+78=1560
Step-by-step explanation:
We know that a summation formula for the first n natural numbers:
1+2+3+...+(n-2)+(n-1)+n=\frac{n(n+1)}{2}
We use the formula, we get
a) 1+2+3+4+...+396+397+398+399=\frac{399·(399+1)}{2}=\frac{399· 400}{2}=399· 200=79800
b) 1+2+3+4+...+546+547+548+549=\frac{549·(549+1)}{2}=\frac{549· 550}{2}=549· 275=150975
c)2+4+6+8+...+72+74+76+78=S / ( :2)
1+2+3+4+...+36+37+38+39=S/2
\frac{39·(39+1)}{2}=S/2
\frac{39·40}{2}=S/2
39·40=S
1560=S
Therefore, we get
2+4+6+8+...+72+74+76+78=1560
