The discontinuous point of function F X = (1 + x) / (1 + x ^ 3) is

X = - 1, which is a removable discontinuity, and its limit is 1 / 3

Finding the discontinuous point of function f (x) = 1 / (x-3) (+ 5)
f(X)=1/(x-3)(x+5)

Discontinuity point, it can be understood that function f (x) has no meaning at the discontinuity point
So let the denominator be zero, and the value of X is zero
(x-3)(x+5)=0,
X = 3, x = - 5, so x = 3, x = - 5 are discontinuities

When doing the calculation of multiplying two digits by two digits, Xiao Mahu regarded 2 on 22 digits of a multiplier as 5. The result is that the incorrect product is more than 69, and what is the correct result
Use arithmetic to make the process clear

Consider 2 on the bits of a multiplier 22 as 5,
That is to say, take this multiplier as 25, 25-22 = 3
As a result, the product will be three times more than the correct multiplier
So, another multiplier = 69 / 3 = 23
therefore
The formula is 22 * 23 = 506
The correct result is 506

When Xiao careless calculates a number multiplied by 0.39, it is regarded as the number multiplied by 0.93, and the difference between the result and the correct result is 8.64

8.64/（0.93-0.39）
=16
16*0.39=6.24

In the calculation of 1.37,7 cycle times a, Xiao Mahu regarded 1.37,7 cycle as 1.37, which is less than 0.7, then a = ()

37a-1.37a = 0.7
007 cycle a = 0.7
7 cycle a = 70
7/9a=70
a=90

(5 out of 8 plus 3 out of 7) multiply 8 by 7
Please! Quick! Good answer, plus 20 points! Quick

(5 out of 8 plus 3 out of 7) times 8 by 7
=5/8×8×7+3/7×8×7
=35+24
=59

1/2+3/4+7/8+15/16+.255/256=?

The original formula is 1-1 / 2 + 1-1 / (2 * 2)
=8-(1/2+1/(2*2).
Use the sum formula of equal ratio sequence
=8-1+1/256
=7 and 1 / 256

1/2+3/4+7/8+… 255 / 256 simple calculation

1/2+3/4+7/8+…… +255/256
=(1-1/2)+(1-1/4)+(1-1/8)+…… +(1-1/256)
=(1+1+1+…… +1)-(1/2+1/4+1/8+…… +1/256)
=1×8-(1-1/256)
=8-255/256
=7 and 1 / 256
I understand. Please accept,
If you have any new questions, please ask for help,

Is 999999 + 1234567 a simple method

9999999+1234567
=9999999+1+1234567-1
=10000000+1234566
=1123456

1111111 * 222222 / 333333
How to calculate skillfully

1111111*222222/333333
=1111111*(111111*2)/(111111*3)
=1111111*2/3

The discontinuous point of function F X = (1 + x) / (1 + x ^ 3) is