F1, F2 are the two focal points of the ellipse X29 + Y27 = 1, a is the point on the ellipse, and ∠ af1f2 = 45 °, then the area of △ af1f2 is___ ．

From the meaning of the title, we can get the conclusion The equation of the ellipse is X29 + Y27 = 1, a = 3, B = 7, and C = A2-B2 = 2, so the focal length | F1F2 | = 22, \| according to the definition of the ellipse, the equation of the ellipse is X29 + Y27 = 1, \| y227 = 1, a = 3, B = 7, which can get C = A2-B2 = 2, so the focal length | F1F2 | F2 | f | f | F2 | 12 | f | 2 | 2 | 2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-1 - | AF1 |) 2 = | AF1 | 2-4 | AF1 | + 8, the solution is | AF1 | = 72, so the area of △ af1f2 is s = 12 | AF1 | · | F1F2 | = 12 × 72 × 22 ×22=72．

Ellipse x ^ 2 / 9 + y ^ 2 / 25 = 1, one end of minor axis is a, the focus is F1, F2, and the perimeter of triangle af1f2 is a The area is .
What I want to ask is not the result, I want to know the solution, and why we can know from the equation that | AF1 | + | af2 | = 10. | F1F2 | = 8, which is what I don't understand most!

The foundation of the building owner is not well grasped,
According to the elliptic equation with focus on Y axis: x ^ 2 / (a ^ 2-C ^ 2) + y ^ 2 / A ^ 2 = 1
Distance from point to two focal points = length of major axis = 2 | a | = 10
And | F1F2 | = 2 | C | = 8

The solution equation: 3 / 2x = 4 / 7, 5 / 11 = 7 / 32
And 4 and 5 / 4 * 6 / 5 =, 9 ÷ 5 and 4 / 1 = fast, use it tonight!

(3/2)x=4/7
x=(4/7)*(2/3)=8/21.
The others are not equations, there are no unknowns

Simple calculation of 125 × 8.88 (two solutions)

1000/8×8.88=1000×1.11=1110
125×（8+0.8+0.08）=1000+100+10=1110

The line y = 2x + 4 intersects the x-axis at a, intersects the y-axis at B, and points c and D are the symmetrical points of point a and point about the origin respectively
1. Finding the function analytic expression of straight line CD
2. Finding the area of quadrilateral ABCD

A (- 2,0), B (0,4), C (2,0), D (0, - 4), let the analytic formula be y = ax + B, substituting C and D into 0 = 2A + B and - 4 = B, so y = 2X-4
S=2×1/2×4×4=16

The price of a commodity is 15% lower than that of last year. The current price is the same as the original price______ %．

1-15% = 85%; so the answer is: 85

It is known that the definition domain of function f (x) is (- ∞, 0) ∪ (0, + ∞), and f (x) is an odd function. When x > 0, f (x) = x2-x + A. if there are exactly two zeros of function g (x) = f (x) - x, then the value range of real number a is ()
A. A ＜ 0b. A ≤ 0C. A ≤ 1D. A ≤ 0 or a = 1

Because f (x) is an odd function, so g (x) = f (x) - x is also an odd function. To make g (x) = f (x) - X have exactly two zeros, we only need to make g (x) = f (x) - X have exactly one zeros when x > 0. From G (x) = f (x) - x = 0, G (x) = x2-x + A-X = x2-2x + a = 0, if △ = 0, that is, 4-4a = 0, the solution is a = 1. If △ > 0, if x > 0, the function If the number G (x) has only one zero point, then G (0) = a ≤ 0, so △ = 4 − 4A ＞ 0A ≤ 0, the solution is a ≤ 0

High school mathematics elective 2-1 (Science)
Simple logical connectives
p: X = 1 is the root of the equation x ^ 3-3x + 2 = 0, Q: x = - 1 is the root of the equation x ^ 3-3x + 2 = 0
How to change its non-p and P and Q
P and Q is x ≠ 1, not the root of the equation x ^ 3-3x + 2 = 0, Q: X ≠ - 1 is not the root of the equation x ^ 3-3x + 2 = 0?
Or = do not have to be changed to ≠
Answer me, just change "yes" to "no", or change it with the symbol?
So the P and Q symbols shouldn't be right?

Non P: x = 1 is not the root of the equation x ^ 3-3x + 2 = 0
P and Q: x = 1 is the root of the equation x ^ 3-3x + 2 = 0 and x = - 1 is the root of the equation x ^ 3-3x + 2 = 0

The original price of a coat was 120 yuan. The price of this coat was reduced by 25% at first, and then sold well, and then increased by 10%. How much is the current price?
Tell me the process of calculation

120*(1-25%)=90
90 * (1 + 10) = 99 yuan

F1, F2 are the two focal points of the ellipse X29 + Y27 = 1, a is the point on the ellipse, and ∠ af1f2 = 45 °, then the area of △ af1f2 is___ ．