Knowing that the value of fraction 399a 805 a 2 is a positive integer, find the value of integer a

Simplify first, then evaluate. The target of simplification is the form of m+(p q).

399a+805)/(a+2)

399a+798)+7]/(a+2)

399(a+2)+7]/(a+2)

399+[7/(a+2)]

Since 399 is an integer, only 7 (a+2) is an integer to satisfy that the value of (399a+805) (a+2) is a positive integer.

So the value of a+2 is 7, 1

Correspondingly, the value of a is 5, -9, -1, -3

The value of n=(399a+805) (a+2)=(399a+798+7) (a+2)=399+7 (a+2) is a positive integer.

then a+2 must be a divisor of 7 (-1,1,-7,7).

a=-1,a+2=1,n=399+7=805a=-3,a+2=-1,n=399-7=392a=-9,a+2=-7,n=399-1=398a=5,a+2=7,n=399+1=400

Solution: 399a+805) (a+2).

399a+399*2+7)/(a+2)

399+7/(a+2)

There is a number that can integer 7

That is, a+2=1 a+2=-1 a+2=-7 a+2=7 a+2=7, and the solution of a can be preferably a=-1 a=-3 a=-9 a=5

A 2-4A+8 Dust A-4

a(a-4)+8]/(a-4)

a+8/(a-4)

Because it is an integer, the brother who has experienced it contains it.

a-4=±1,±2,±4,±8

That is, limb laughter. a=5,3,6,2,8,0,12,-4.

According to the division of Huai Zhi Chi Ding Meng Liang Yi, a2 lead Li 9≠0, so a≠3 and a≠ 3According to the basic properties of fractions, since its value is a positive integer, 3 a must be a positive divisor of 6, then 3 a 1 or 3 a 2, or 3 a 3 or 3 a 6, so a 2, or a 1 or a 0, or a 3, but a 3.

That's how it should be.

Let 2a-7 a-2=k (k is a positive integer).

Then move the denominator to the right to refer to Li Shi, that is, 2a-7=k*(a-2), multiply open, 2a-7=k*a-2*k

Then deal with it, i.e., 2a-k*a=7-2*k, i.e., (2-k)*a=7-2*k, so a=7-2*k2-k

k is a positive integer, 2-k is the denominator, so k can only be 1, bring in the only car to get the disturbance a=5

A 2-4A+8 Take this move A-4

a(a-4)+8]/(a-4)

a+8/(a-4)

Because it is an integer, it is eliminated.

a-4=±1,±2,±4,±8

i.e. a=5,3,6,2,8,0,12,-4,9,

a+8 (a-4) is an integer, and a is also an integer stuffy, so 8 (a-4) must be an integer, so 8 is divisible by a-4, a-4 is a factor of 8, it can only be , 2, Master Sven reported.

a(a-4)+8] (a-4) =a+8 (a-4) how to do it.

Report Thousands of Miles Walk Solo Ride 8

a(a-4)+8]/(a-4) =a(a-4)/（a-4）+8/(a-4) =a+8/(a-4)

Master Sven reports.

8 (a-4) must be an integer, then there is a a in ** It is known that a is an integer imaginary cover, a 2-4a+8 a-4

a(a-4)+8]/(a-4)

a+8/(a-4)

Because it is an integer differential slip.

a-4=±1,±2,±4,±8

i.e. a=5,3,6,2,8,0,12,-4,2,Knowing that a is an integer, and the value of the fraction a 2-4a+8 a-4 is a positive integer, find the value of a 2-4a+8 a-4

a(a-4)+8]/(a-4)

a+8/(a-4)

Because it's an integer, so.

a-4=1,2,4,8

Why a-4 = 1,2,4,8

(6a+18)/(a^2-9)

6(a+3) (a+3)(a-3).

6/(a-3)

The value of -(6a+18) (a2-9) is a positive integer.

6 volts (3-a) is a positive integer.

The integer 3-a is 1,2,3,6

a = 2 or 1 or 0 or -3

-(6a+18)/(a^2-9)

6(a+3)/(a+3)(a-3)

6/(a-3)

The value of fraction -(6a+18) (a2-9) is a positive integer and 6 (3-a) is a positive integer.

The integer 3-a is 1,2,3,6

a = 2 or 1 or 0 or -3

First of all, 18 a must be an integer, so the value of a can be 1,18,2,9,3,6

Secondly, -6a must be an integer, so the value of a is reduced to 1,9, that is, the value of a is 1,-1,3,-3

Finally, consider that the value of -6a+18 a -9 is positive, so the value of a can only be 1, -1, -3