Two and a half + three and a third + four and a quarter + five and a fifth + six and a sixth =? A question of Jiazhou cup in Leshan City

Two and a half + three and a third + four and a quarter + five and a fifth + six and a sixth =? A question of Jiazhou cup in Leshan City

Simple, the original formula = (2 + 3 + 4 + 5 + 6) + (1 / 2 + 1 / 3 + 1 / 6 + 1 / 4 + 1 / 5) = 21 and 9 / 20

Given the image of the function x & # 179; + ax & # 178; + BX 5, the tangent equation of x = 1 is y = - 12x to find the analytic expression of FX. When x belongs to [- 3,2], find the monotone interval and the maximum value of the function

(1) (2) f '(x) = 3x ^ 2 + 6x-21 = 0, x = - 1-2 √ 2, x = - 1 + 2 + 2 √ 2, f (- 1-2 √ 2) = 2

What's the rule of 2 / 7.3/26.4/63.5/124
What's next?

The third power of (n + 1) / n-1
The next one is 6 / 215

The derivative of the X / K power of E is

Guo Dunyong replied:
F(x)=e^x/k
F(x)′=e^x/k×(x/k)′=(e^x/k)/k

How much is 1 minus (5 / 12 plus 1 / 3) plus 1 / 3?

=1-5/12-1/3+1/3
=7/12+0
=7 out of 12

If polynomial x ^ 4 + (m-1) x ^ 3 + 2x ^ 2-3x + 1 does not contain x ^ 3x term, then M =?

X ^ 4 + (m-1) x ^ 3 + 2x ^ 2-3x + 1 does not contain x ^ 3x items
The x ^ 3 coefficient is 0
So M-1 = 0
m=1

The mass of a bottle is 20g, the mass of a bottle filled with water is 120g, and the mass of a bottle filled with alcohol is 105g. Is this kind of alcohol pure alcohol? (explain by calculation) (the density of alcohol is found to be 0.8 × 103kg / m3 from the density table)

M alcohol = 105g-20g = 85g, m water = 120g-20g = 100g, ∵ ρ = MV, ∵ V alcohol = V water = m water, ρ water = 100g1 g / cm3 = 100cn3, ρ alcohol = m alcohol, V alcohol = 85g100cm3 = 0.85g/cm3 = 0.85 × 103kg / m3. Because the density of alcohol is 0.8 × 103kg / m3, this kind of alcohol is not pure alcohol

What is it after 2 and 4 / 15, 3 / 4 and 1 and 9 / 20

2+4/15=34/15=136/60
3/4=45/60
1+19/20=39/20=117/60

5 divided by 11 is calculated by a simple method

(8.36-5.5)/11
=8.36/11-5.5/11
=0.76-0.5
=0.26

Calculation questions: 198 and 178;

198²=(200-2)²=200²-2×200×2+2²=40000-1600+4=39204