Question

*The sum of 2/7 and 3/7 is 5/b. What is the value of b?* 1️⃣ 7 2️⃣ 5 3️⃣ 3 4️⃣ 4

Answer 1

Answer:

Given:-

The sum of $\dfrac{2}{7}$ and $\dfrac{3}{7}$ is $\dfrac{5}{b}$. What is the value of b?

To Find:-

The value of b.

Note:-

●》Here, for finding "b" we will add the "first term" to "second" = "their sum" and also by "transposing".

●》Transposing - For finding the unknown value, we need to transposed other side the known value and during transposing, signs are also changed. For example - Divisional becomes Multiple, Multiple becomes Divisional.

Solution:-

$\huge\red{ \dfrac{2}{7} + \dfrac{3}{7} = \dfrac{5}{b}}$

$\huge\red{ \ \ \ \ The \ \ value \ \ of \ \ b = ?}$

☆ According to note first point~

▪︎$First \ \ term + Second \ \ term = Their \ \ sum$

▪︎$\dfrac{2}{7} + \dfrac{3}{7} = \dfrac{5}{b}$

▪︎$\dfrac{5}{7} = \dfrac{5}{b}$

☆ According to note second point ( we are transposing "b" )~

▪︎$\dfrac{5}{7} × b = 5$

▪︎$\dfrac{5}{7}b = 5$

☆ Now, we will transpose $\dfrac{5}{7}$ for "b" to be calculated~

▪︎$b = 5 ÷ \dfrac{5}{7}$

☆ Reciprocating the divided term~

▪︎$b = 5 × \dfrac{7}{5}$

▪︎$b = \dfrac{35}{5}$

☆ After dividing by 5~

▪︎$b = 7$

$\huge\pink{The \ \ value \ \ of \ \ b = 7}$

Checking:-

♤ Let's check for "b" that First term + Second term = Their sum or not.

• $First \ \ term + Second \ \ term = Their \ \ sum \implies ?$

• $\dfrac{2}{7} + \dfrac{3}{7} = \dfrac{5}{b} \implies ?$

♤ Applying the value of "b"~

• $\dfrac{2}{7} + \dfrac{3}{7} = \dfrac{5}{7} \implies ?$

• $\dfrac{5}{7} = \dfrac{5}{7} \implies ?$

$\huge\green{Hence, Proved : The \ \ value \ \ of \ \ b = 7}$

Answer:-

Hence, the value of "b" = 7 ( Option 1 ).

:)

Answer 2

Answer:

The value of b is 7.

Step-by-step explanation:

Assumption,

Let the value, 2/7 be 'x'

Let the value, 3/7 be 'y'

Let the value, 5/b be 'z'

Given,

The sum of 2/7 and 3/7 is 5/b.

i.e. x + y = z

To find,

The value of 'b' present in the denominator of 5/b

Calculation,

As x + y = z

⇒ 2/7 + 3/7 = 5/b

Considering L.H.S

L.H.S = 2/7 + 3/7

As the denominator of both the terms is same we can add the numerators of the fraction and divide by 7.

(If the denominators are not same then we have to take L.C.M of the denominators and then add as above).

So, L.H.S = (2 + 3)/7

⇒ L.H.S = 5/7

Equating L.H.S = R.H.S

⇒ 5/7 = 5/b

As the numerators are equal then the denominators must be equal for maintaining the equality.

Therefore, the value of b is 7.

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