Question

. If a varies inversely as b - 4, and if a=5 when b 1/2 find a when b=-1​

Answer 1

The value of a is 3.5.

Step-by-step explanation :

Given : If a varies inversely as b - 4, and if a=5 when b=1/2.

To find : The value of a when b=-1​ ?

Solution :

If a varies inversely as b-4,

i.e. $a\propto \frac{1}{b-4}$

$a=\frac{k}{b-4}$

Where, k is constant of proportional

Substitute, a=5 when $b=\frac{1}{2}$

$5=\frac{k}{\frac{1}{2}-4}$

$5=\frac{k}{\frac{-7}{2}}$

$-2k=35$

$k=-\frac{35}{2}$

$k=-17.5$

Now, $a=\frac{-17.5}{b-4}$

Substitute b=-1,

$a=\frac{-17.5}{-1-4}$

$a=\frac{-17.5}{-5}$

$a=3.5$

Therefore, the value of a is 3.5.

#Learn more

If x varies inversely as (y2 - 1) and x is equal to 24 when y = 10, then the value of x when y = 5 is

https://brainly.in/question/2425325

Answer 2

Step-by-step explanation:

Step-by-step explanation :

Given : If a varies inversely as b - 4, and if a=5 when b=1/2.

To find : The value of a when b=-1 ?

Solution :

If a varies inversely as b-4,

i.e. a\propto \frac{1}{b-4}a∝b−41

a=\frac{k}{b-4}a=b−4k

Where, k is constant of proportional

Substitute, a=5 when b=\frac{1}{2}b=21

5=\frac{k}{\frac{1}{2}-4}5=21−4k

5=\frac{k}{\frac{-7}{2}}5=2−7k

-2k=35−2k=35

k=-\frac{35}{2}k=−235

k=-17.5k=−17.5

Now, a=\frac{-17.5}{b-4}a=b−4−17.5

Substitute b=-1,

a=\frac{-17.5}{-1-4}a=−1−4−17.5

a=\frac{-17.5}{-5}a=−5−17.5

a=3.5a=3.5

Therefore, the value of a is 3.5.

#Learn more

If x varies inversely as (y2 - 1) and x is equal to 24 when y = 10, then the value of x when y = 5 is