16(x-y)²-25(x+y)²

16(x-y)²-25(x+y)²

16(x-y)²-25(x+y)²
= (4x-4y)²-(5x+5y)²
= ( 4x-4y + 5x+ 5y ) ( 4x- 4y - 5x - 5y)
= (5x + y )( -x - 9y)
= - (5x + y )( x + 9y)
Benefactor, I see your bones are strange,
He is a man of noble bearing and wisdom,
He is a unique talent in the Wulin
If you devote yourself to study, you will become a great tool in the future,
I have a little test, please click next to the answer
"Choose as satisfactory answer"

9 / 10 unknowns = 3 / 40 x 5 / 21

9 out of 10 x = 3 out of 40 x 5 out of 21
x=1/56*10/9
x=5/252

Equation: 10 / 4-x (unknown) - 3 / 3 x (unknown) minus 5 = x (unknown) + 1

Take 12 on both sides
30-3x-4x+20=12x+12
50-7x=12x+12
19x=38
x=2

What day is new year's day in 2008

Tuesday

The "100 km acceleration time" of a small car is the minimum time for a car to accelerate from a standstill to 100 km / h. for three types of cars, a, B and C, the acceleration time is 11.3s, 13.2s and 15.5s respectively, and the average acceleration is calculated

Acceleration a = (VT VO) / T with VO as the positive direction, a and VO in the same direction (acceleration) a > 0; reverse direction a

In RT △ ABC, angle c = 90 °. 1. If two right angle sides a and B are known, then C =, tanb =, angle A=

c=√（a²+b²）
tanB=b/a
tanA=a/b
A=arctan（a/b）

When car a runs three-quarters of the whole journey and car B runs 60% of the whole journey, the distance between the two cars is 28 km, and the two places are opposite
How many kilometers away?

60% X - (1-75%) x = 28 km x = 80 km, that is, the distance between AB and ab is 80 km

The number of times and items of x2y3-3xy3-2 are ()
A. 5，3B. 5，2C. 2，3D. 3，3

The number of times and items of x2y3-3xy3-2 are 5 and 3 respectively

Two cars leave from a and B at the same time. When they first meet, they are 90km away from A. then they go on at the same speed. When they arrive at each other's station, they immediately return on the same way. When they meet again, the distance from a is 65% of the distance between a and B. how many meters is the distance between a and B?

Set the whole distance to x km
The total distance of car a is the distance from the whole journey to place B (35% of the whole journey)
Because the first encounter a car walk 90 km, that is to say, in a whole journey a walk 90 km, so to the second encounter a total walk 90 × 3 = 270 km, minus the distance from B is the whole journey
270-35%x=x
x=200

Given the equation of a circle, we can find the linear system equation of all tangent lines in the circle
Given the equation of circle x ^ 2 + y ^ 2 + DX + ey + F = 0, we can find the linear system equation of all tangents in the circle

X ^ 2 + y ^ 2 + DX + ey + F = 0 = > (x + D / 2) ^ 2 + (y + E / 2) ^ 2 = - F + D ^ 2 / 4 + e ^ 2 / 4, so any point on the circle can be expressed as (- D / 2 + radical (- F + D ^ 2 / 4 + e ^ 2 / 4) cos θ, - E / 2 + radical (- F + D ^ 2 / 4 + e ^ 2 / 4) sin θ) derivation of X on both sides = > 2x + 2yy '+ D + ey' = 0 = > y '= (- d-2x) / (2Y + e) = - 1 / Tan θ = >