Question

(5a+2b) : (a+b) = 9:7
find a:b ​

Answer 1

5a+2b/a+b=9/7

35a+14b=9a+9b

35a-9a=9b-14b

26a=-5b

a/b= -5/26

Answer 2

Answer:

The required ratio is -5:26

Step-by-step explanation:

In this respective sum, we have been mentioned that the ratio of two expressions is 9: 7. We first will just apply the method of cross multiplication to solve this as follows:

$\frac{5a + 2b}{a+b} = \frac{9}{7}$

⇒ 7(5a+2b) = 9(a+b)

⇒ 35a + 14b = 9a + 9b

⇒ 35a - 9a = 9b - 14b

⇒ 26a = -5b

⇒$\frac{a}{b}$ = $\frac{-5}{26}$

Therefore the ratio of a: b is -5: 26