How much is 1 + 3 + 5 + 7. + 39

How much is 1 + 3 + 5 + 7. + 39

=(1+39)x10=400

If you add three fifths to a number and subtract three fourths, it will be equal to one. To find the number, you need to synthesize the formula

x+3/5-3/4=1
x=1+3/4-3/5=23/20

How to solve the equation 4.7 * 6 + 5x = 39.7

4.7*6+5x=39.7
28.2+5x=39.7
5x=39.7-28.2
5x=11.5
x=11.5/5
x=2.3

Let y = F & nbsp; (x) satisfy f & nbsp; (x + 1) = F & nbsp; (x) + 1, then the number of roots of the equation F & nbsp; (x) = x is ()
A. Infinite B. finite C. no or finite D. no or infinite

∵ function y = F & nbsp; (x) satisfies F & nbsp; (x + 1) = F & nbsp; (x) + 1, ∵ f (x) = f (x-1 + 1) = f (x-1) + 1 = f (X-2) + 1 + 1 = f (0) + x = x & nbsp; & nbsp; either f (0) = 0, the number of roots of the equation F & nbsp; (x) = x is infinite & nbsp; or F (0) is not equal to 0, the equation F & nbsp; (x) = x has no solution, so D is selected

English translation
Computer system integration
Computer system integration
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Software development,Internet behavior management,data document security and encryption
Computer / security system integration, information outsourcing services and training
Computer/security system integration,informationization outsourcing service and training
Business card size is limited, "abbreviation" professional abbreviations, such as: DHCP, STMP, B2B, HTML, www

Computer system integration=CPT ST ITG
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Computer/security system integration=CPT/STY ST ITG
informationization outsourcing service and training=IFTN OTG SVE and TIG

In parallel circuit, help me infer that r = R1 + R2 / r1r2, how to get it?
Reasoning according to R / 1 = R1 / 1 + R2 / 1

I=I1+I2=U/R1+U/R2=U/[（R1*R2）/（R1+R2）]
R total = R1 * R2 / (R1 + R2)
1/R=1/R1+1/R2=R2/R1*R2+R1/R1*R2=(R1+R2)/R1*R2
R=R1*R2/（R1+R2)

It is known that the sum of binomial coefficients of all terms in the (1 + 2x) ^ n expansion is 1024, and the maximum term of coefficient in the expansion is obtained

Because cN0 + cN1 + cn2 +Cnk+… +Cnn=2^n =1024
So n = 10
Let R be the largest, then C (10, R) * (2) ^ (R) > = C (10, R + 1) * (2) ^ (R + 1)
C(10,r)*(2)^(r)>=C(10,r-1)*(2)^(r-1)
So there is an inequality system R + 1 > = 2 (10-r)
2（11-r）>=r
So r is 20 / 3

If a 3 / a = 5 / B, then AB is proportional to ()

I think ab = 15 (3 × 5)

Change the quadratic equation of one variable into a general form, and then write out the coefficients of quadratic term, the first term and the constant term
1、6x-1=x（4x-3）
2、x^2-5x=-3

1、
6x-1=4x²-3x
4x²-9x+1=0
a=4,b=-9,c=1
2、
x²-5x+3=0
a=1,b=-5,c=3

5:3:26 = 6x

"Abc81946789" Hello, I'm glad to answer for you!
3 / 5:26 = 6x
3 / 5 △ 26 = 6x
3 / 5 = 156x
X=260
There is a mistake in the process of upstairs solution, please correct it