Question

7а+3в/3а-в если а/а+в 3/4

Answer 1

a/(a+b)=3/4

3(a+b)=4a

3a+3b=4a

4a-3a=3b

a=3b

$\frac{7a+3b}{3a-b} =\frac{21b+3b}{9b-3b} =\frac{24b}{6b} =4$

Answer 2

To simplify the expression, we'll use the given relationship between "a" and "a+в":

a/(a+в) = 3/4

Now, let's find the values of "a" and "в" using this relationship:

Cross-multiply the fraction:

4a = 3(a + в)

Now, expand the right side:

4a = 3a + 3в

Next, isolate "в" on one side of the equation:

4a - 3a = 3в

Simplify:

a = 3в

Now, let's substitute this value of "a" back into the given expression:

(7а + 3в) / (3а - в)

Replace "a" with "3в":

(7(3в) + 3в) / (3(3в) - в)

Simplify further:

(21в + 3в) / (9в - в)

Combine like terms in the numerator:

24в / 8в

Now, divide "в" from the numerator and denominator:

24 / 8

Finally, reduce the fraction:

3

So, the simplified expression is 3.