Question

If (3x+1):(5x+3) is the triplicate ratio of 3:4,find the value of x

Answer 1

@chmvijay

Answer 2

This can be rewritten as:
\[\frac{ (3x+1) }{ (5x+3)} = \frac{ 3 }{ 4 }\]

Can you use cross-products to get this from fraction form to fraction-less equations?
Then you can perform the same mathematical functions ( +, -, *, /) to each side to keep the two sides equal. Solve to get the form x = ? .

Answer 3

shouldn't 3 and 4 be 64 ans 27 as their respective cubes..??

Answer 4

Actually, I am corrected. I just Google-ed "triplicate ratio" and I think this means that the cubes of each binomial are in the ratio 3 to 4. ( http://www.thefreedictionary.com/Triplicate+ratio)

Answer 5

triplicate ratio of a:b is a^3 : b^3

Answer 6

Or...the wording suggests that it's the triplicate ratio of 3 to 4? (27 to 64 as you said). Sorry about that!
Then the proportion would be:
\[\frac{ 3x+1 }{ 5x + 3} = (\frac{ 3 }{ 4 })^{3} = \frac{ 27 }{ 64 }\]

Answer 7

What do you get as your answer for x ? I can tell if it matches what I got.

Answer 8

9/11

Answer 9

I don't get that as my answer. As an intermediate, I got:
192 x + 64 = 135 x + 81, from cross-multiplying.
Then I used algebra to simplify to get x = ?
(also verified my answer, so it's correct). What do you get as your new answer?

Answer 10

57x = 17
x = 17/57

Answer 11

That's correct! Good work! :)

Don't forget to close the question.

Answer 12

yes x=17/57 is correct