If the polynomial (a + 1) X4 - (1-B) X5 + x2-2 is a quadratic polynomial about X, then a + B=______ ．

If the polynomial (a + 1) X4 - (1-B) X5 + x2-2 is a quadratic polynomial about X, then a + B=______ ．

According to the meaning of the question: a + 1 = 01 − B = 0, the solution: a = − 1b = 1, a + B = - 1 + 1 = 0

If the sum of the second power of polynomial x-x and polynomial KX + 1 is the second power of X + 1, then the value of K is

x²-x+kx+1=x²+1;
k-1=0;
k=1;

Add a polynomial to the second power of - 2 + x-x to get the second power of X-1

Polynomial + (- 2 + X + X & sup2;) = x & sup2; - 1
Polynomial = x & sup2; - 1 - (- 2 + X + X & sup2;)
=1-x

Rational multiplication and division
N is a natural number,
Calculation: the sum of [5 times (- 1) to the (2n + 1) power] and [4 times (- 1) to the (2n + 2) power] is ()

The (2n + 1) power of (- 1) is odd, so it is equal to - 1
The (2n + 2) power of (- 1) is even, so it is equal to 1
The final results are as follows: - 1

Eight times a quarter plus fifteen divided by four minus twenty-one times zero twenty-five

=2+3.75-5.25=0.5

If the solution set of inequality - 1 / 2x ^ 2 + 2x > MX about X is 0
The teacher said "m = 1". Why? I think there are two situations. Both solutions need to be written

It's M = 1, because the two equations are 0 and 2. By using Weida's theorem, the sum of the two equations equals - B / A, M = 1 is obtained directly

The thickness of steel plate is 20 mm, how many kg is it per square meter, and the steel density is 7.85

It's very simple, 20 x 7.85 = 157kg, the density of steel is 7.85t/m3, the conversion is just 1mm, the thickness per square meter weight is 7.85kg, so the thickness of 20mm is 20 x 7.85, the unit is kg

There is a batch of cement on the construction site, 30% of which is used for the first time, and 60 tons for the second time. At this time, there are still two fifths of all the cement left. How many tons of this batch of cement are there in total
What's the formula

200 tons!
If 30% is used in the first time and there is still 40% left, then 30% will be used in the second time, that is 60 tons. 60 / 30% = 200 tons
It's just an unknown number

A cylindrical steel with a bottom of 12,56 square decimeters and a height of 4,5 decimeters is melted and cast into a cone with a bottom diameter of 6 decimeters. How high is the cone

12.56×4.5=56.52 6÷2=3 3×3×3.14=28.26
56.52 × 3 △ 28.26 = 6 decimeters

A number is a factor of 72 and a multiple of 4. How many such numbers are there?
fast

The multiple of 4 within 72: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72
72: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72
The factor of 72 is a multiple of 4. There are six numbers (4, 8, 12, 24, 36, 72)