a. B, C, D are positive integers, B / a = (4d-7) / C, (B + 1) / a = 7 (D-1) / C to find the value of C / A What about D / a

b/a=(4d-7)/c
c/a=(4d-7)/b
(b+1)/a=7(d-1)/c
c/a=7(d-1)/(b+1)
So: (4d-7) / b = 7 (D-1) / (B + 1)
7b(d-1)=(4d-7)(b+1)
7bd-7b=4db+4d-7b-7
3db=4d-7
c/a=(4d-7)/b=3db/b=3d

RELATED INFORMATIONS

1. If a, C, D are integers and B is a positive integer, and a + B = C, B + C = D, C + D = a is satisfied, then the maximum value of a + B + C + D is () A. -1B. -5C. 0D. 1
2. -4/9,10/9,4/3,7/9,1/9 A．7/3 B 10/9 C -5/18 D -2 -4/9,10/9,4/3,7/9,1/9 A．7/3 B 10/9 C -5/18 D -2
3. Given that a + B + C = 10 / 9, B-A = 1 / 2, B-C = 7 / 18, what are the numbers of a, B, C and C Please
4. 3 5 7 （） 13 A.8 B.9 C.10 D.11 Which one?
5. What are the known numbers a + B + C = 9 / 10, B-A = 2 / 1, B-C = 18 / 7, a, B, C? emergency Look for ideas!
6. In the parallelogram ABCD, the values of angle A: angle B: angle c: angle D can be a1:2:3; 4, b1:2:2:1, c1:1:2:2, d2:1:2:1 In the parallelogram ABCD, the values of angle A: angle B: angle c: angle D can be a1:2:3; 4, b1:2:2:1, c1:1:2:2, d2:1:2:1
7. Given that ABCD is four different integers, (A-1) (B-1) (C-1) (D-1) = 4, find the value of a + B + C + D
8. If a, B, C, D are mutually unequal integers, and ABCD = 49, find the value of (a + B + C + D-1) ^ 2013
9. Let ABCD be all positive numbers, ABCD = 1, then the minimum value of a ^ 4 + B ^ 4 + C ^ 4 + D ^ 4 is? Where a, B, C and D are?
10. Given a = 3, B = - 5, C = 7, find the following values 2a-c; a-b-c
11. Given that a, B, C are all positive integers, and B / a = 4d-7 / C, B + 1 = 7 (D-1) / C, what is the value of C / a? What is the value of D / b? To analyze. Fast. Urgent
12. A. If there are three numbers B and C, 2 / 3 of a equals 4 / 7 of B, 2 / 3 of B equals 4 / 7 of C, and C is 1 / 3 larger than a, then B is A. If 23 of a is equal to 47 of B, 23 of B is equal to 47 of C, and C is 13 greater than a, then B is () There are 15 students, each student has a number, which is 1 to 15 in turn. No. 1 wrote a five digit number, No. 2 said: "this number can be divided by 2", No. 3 said: "this number can be divided by 3", No. 4 said: "this number can be divided by 4" Students on the 15th said: "this number can be divided by 15.". The students of No. 1 checked one by one. Only the two students with consecutive numbers said that they were wrong, while the others were right
13. If a: B equals 2:5 and B: C equals 3:7, then a: B: C equals 3:7
14. If 3 (a + C) = 2 (B-C), then what is C equal to
15. If 1A: 1b: 1C = 2:3:4, then a: B: C=______ ．
16. If we know (1 + A + 1 / B + 1 / C + 1 / D) + 1 / 36 + 1 / 45 = 1, and a, B, C and D are just four continuous natural numbers, we can find the sum of a, B, C and D Today is the day,
17. There are four natural numbers a, B, C and D. the least common multiple of a and D is 36, and the least common multiple of C and D is 90 a. What is the least common multiple of B, C and D? The least common multiple of a and B is 36,
18. (A / 1 + B / 1 + C / 1 + D / 1) + 36 / 1 + 45 / 1 = 1 a B C D is four continuous natural numbers a + B + C + D =? Urgent need
19. There is a problem: ABCD four natural numbers, followed by less than 16, known a is 3 times D, find the value of ABCD, how to do ah Such as the title
20. a. B, C, D are four different natural numbers, and a * b * c * d = 1995, what is the minimum value of a + B + C + D?