Observe the following monomials and write the nth a,-2a²,4a³,-8a^4,16a^5

Observe the following monomials and write the nth a,-2a²,4a³,-8a^4,16a^5

-The nth power of (- 2A) / 2

Are these formulas monomials?
1.x^y
2.logx
3.e^x
4.sinx

1. X ^ y, when y is a positive integer, it is a monomial,
Nothing else

The polynomial a2x3 + ax2-4x3 + 2x2 + X + 1 is a quadratic polynomial about X. it is urgent to find A2 + 1 / A2 + A within today!

Peripheral 2: A & sup2; X & sup3; + ax & sup2; - 4x & sup3; + 2x & sup2; + X + 1 = (A & sup2; - 4) x & sup3; + (a + 2) & sup2; + X + 1 ∵ is a quadratic polynomial about X ∵ a & sup2; - 4 = 0, that is, (a + 2) (A-2) = 0, the solution is a = - 2 or a = 2A + 2 ≠ 0, the solution is a ≠ - 2 ∵ a = 2 ∵ A & sup2; + 1 / A & sup2; + A = 2 & sup2

1+3+5+7+… +197+199．

（199-1）÷2+1，=99+1，=100；（199+1）×100÷2，=20000÷2，=10000．

What is 1 + 3 + 5 + 7 + 9 + 11 +... + 199?

Number of items: (199-1) △ 2 + 1 = 100
（1+199）×100÷2
=20000÷2
=10000

How to calculate from 1 + 3 + 5 + 7 to 199

1 to 199, a total of 199, of which the first 99 are 1 to 99, the middle number is 100, the last 99 are 101 to 1991 to 99, odd number is 50, even number is 49, 1 + 3 + 5 + 7 +. + 99 = (1 + 99) x (50 / 2) = 2500101 to 199, odd number is 50, even number is 49, so, 101 + 103 +. 199 = (101 + 199) x

How to calculate 1-3 + 5-7 + 9-10 + 11... + 197-199?
The result is 2, - 2, - 100,

-100
Directly divided into 1-3,5-7,9-10 197-199 are all negative numbers
Add these negative numbers, it's definitely not 2 and - 2

1, 3, 5, 7, 9, 11, what's 199th
How to do a question like this

There are 198 numbers in front of the 199th number. Each number is 2 larger than the previous number, which is larger than the first number
2*（199-1）=396
And the first number is 1, so this number:
198 * 2 + 1 = 397

1*1+2*3+3*5+4*7.+99*197+100*199=

General term an = n (2n-1) = 2n ^ 2-N
Sn=(1/3)n(n+1)(2n+1)-n(n+1)/2=(1/6)n(n+1)(4n-1)
So S100 = 671650

Calculate 1 * 1 + 2 * 3 + 3 * 5 + 4 * 7 +. + 99 * 197 + 100 * 199
be as quick as ever you can

1+2+3+4+...+n=n(n+1)/21*1+2*2+3*3+4*4+...+n*n=n(n+1)(2n+1)/61*1+2*3+3*5+4*7+.+99*197+100*199=1*1+2*3+3*5+4*7+.+99*197+100*199+（1+2+3+4+5+...+99+100)-(1+2+3+4+5+...+99+100)=(1*1+1)+(2*3+2)+(3*5+3)+(4*...