Question

the sum of three numbers is 28 .the second is three times the first and the third is 7 less than the second .what is the number​

Answer 1

Given:

Three numbers whose

• Sum = 28
• First Number = x
• Second Number = 3x
• Third Number = 3x - 7

What To Do:

We have to find those three numbers.

How To Do:

According to the question,

• The equation is (x) + (3x) + (3x - 7) = 28 and solve the eqaution.

Solution:

(x) + (3x) + (3x - 7) = 28

Remove the brackets in LHS,

⇒ x + 3x + 3x - 7 = 28

Solve the terms in LHS,

⇒ 7x - 7 = 28

Take 7 to RHS,

⇒ 7x = 28 + 7

Add the numbers,

⇒ 7x = 35

Take 7 to RHS,

⇒ x = $\dfrac{35}{7}$

Divide 35 by 7,

⇒ x = 5

Now substitute the value,

• First Number = x = 5
• Second Number = 3x = 3 × 5 = 15
• Third Number = 3x - 7 = 3 × 5 - 7 = 15 - 7 = 8

∴ Thus, the three numbers are 5, 15 and 8 respectively.

Verification:

x + 3x + 3x - 7 = 28

Substitute the value,

⇒ 5 + 3(5) + 3(5) - 7 = 28

Solve the brackets,

⇒ 5 + 15 + 15 - 7 = 28

Add 5, 15 and 15,

⇒ 35 - 7 = 28

Subtract 7 from 35,

⇒ 28 = 28

∴ LHS = RHS

∴ Hence, verified.

Answer 2

Answer:

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