Question

Solve for b a equals A=3(b + C)

Answer 1

Answer: Correct option is A)

It is given that a:(b+c)=1:3 and c:(a+b)=5:7 and we solve these expressions

Step-by-step explanation:

b+c

a

​

=

3

1

​

⇒3a=b+c

⇒3a−b=c....(1)

a+b

c

​

=

7

5

​

⇒7c=5(a+b)

⇒7c=5a+5b....(2)

Multiplying the first equation by 7 we get:

7(3a−b)=7c

⇒7c=21a−7b....(3)

Now, subtracting equation 2 from equation 3, we have:

7c−7c=(21a−7b)−(5a+5b)

⇒0=21a−7b−5a−5b

⇒16a=12b

⇒b=

12

16a

​

⇒b=

3

4a

​

Substituting the value of b in equation 1:

3a−

3

4a

​

=c

⇒c=

3

9a

​

−

3

4a

​

⇒c=

3

9a−4a

​

⇒c=

3

5a

​

Now, lets find the value of b:(a+c) as shown below:

a+c

b

​

=

a+

3

5a

​

3

4a

​

​

=

3

3a

​

+

3

5a

​

3

4a

​

​

=

3

8a

​

3

4a

​

​

=

3

4a

​

×

8a

3

​

=

8a

4a

​

=

2

1

​

=1:2

hence, b:(a+c)=1:2.