2x²-9x+7>0

2x²-9x+7>0

Pre factorization
(2x-7)(x-1)>0
Get the range from the function image
{x|x7/2}

How to calculate 9x & # 178; - 2x & # 178

9x & # 178; - 2x & # 178; merge the same class directly
=(9-2)x²
=7x²

Describe good English words
Like good, nice, best

pretty good.
wonderful
unique
terrific
smashing

Why can the square difference of two consecutive odd numbers be divided by 8
[not] prove whether it can be divided or not! [why it can be divided by 8]! Don't make a mistake

K is an integer, 2K + 1 and 2k-1 are continuous odd numbers, (2k + 1) ^ 2 - (2k-1) ^ 2 = 4K ^ 2 + 4K + 1 - (4K ^ 2-4k + 1) = 4K ^ 2 + 4K + 1-4k ^ 2 + 4k-1 = 8kk is an integer, 8K can be divided by 8

If f (x) satisfies the following condition f (x + y) = f (x) * f (y), and X tends to 0, G (x) = 1, f (x) = 1 + XG (x), how can we prove that this function is differentiable everywhere?
High number

Certification:
Let the infinitesimal of X be DX
When x tends to 0, DX tends to 0
When x tends to zero, G (x) = 1, f (x) = 1 + XG (x)
F (o) tends to 1
f'(x)=[f(x+dx)-f(x)]/[(x+dx)-x]
=[f(x)*f(dx)-f(x)]/dx
When x tends to 0, DX tends to 0, f (DX) = f (0) = 1
f'(x)=f(x)*[f(dx)-1]/dx
=f(x)*[dx*g(dx)]/dx
=f(x)*g(dx)
=f(x)*1=f(x)
Therefore, f (x) is derivable

55 / 54 * 37 =? How to use a simple method to calculate?

(55/54)*37
=(1+1/54)*37
=1*37+1/54*37
=37+37/54
=37 and 37 / 54

What is the solution of X squared-3x-2 = 0

X squared - 3x-2 = 0
Then x & sup2; - 3x + 9 / 4 = 2 + 9 / 4
Then (x-3 / 2) & sup2; = 17 / 4
Then x-3 / 2 = ± √ 17 / 2
Then x = 3 / 2 ± √ 17 / 2

Verification: if a line and two intersecting planes are parallel, then the line and their intersecting lines are parallel

It is known that: as shown in the figure, α ∩ β = B, a ∩ α, a ∥ β. Prove: a ∥ B. prove: from a ∩ α, the plane passing through a intersects with α in line C, then a ∥ C, similarly, let the plane passing through a intersect with β in line D, then a ∥ D, from the parallel axiom: C ∥ D, then C ∥ β, then C ⊂ α, α ∩ β = B, so C ∥ B, and a ∩ C, so a ∥ B

Water, steam and ice are made of water_____ Constituted
Such as the title

H2O

What is the physical meaning of a in F = ma
What is the unit of a

Acceleration
If you change the motion state of an object, it must have an acceleration
Meters per second square
m/s^2