Fifteen years from now rohans age is will be four times his present age what is rohans present age

Let Ravi's present age = x years

    4 times the present age = 4 x = 4x years

                                      x = (-15) (-3) = 5

∴          Ravi's present age = 5 years.

Solution:

Let's form a linear equation for the given problem statement.

Let the present age of Ravi be x years.

According to the question, 15 years from now, Ravi’s age will be 4 times his present age

x + 15 = 4x

x - 4x = -15

-3x = -15

x = -15/(-3)

x = 5

Thus, Ravi’s present age is 5 years.

☛ Check: NCERT Solutions for Class 8 Maths Chapter 2

Video Solution:

Fifteen years from now Ravi’s age will be four times his present age. What is Ravi’s present age?

NCERT Solutions Class 8 Maths Chapter 2 Exercise 2.2 Question 12

Summary:

Fifteen years from now Ravi’s age will be four times his present age. Ravi’s present age is 5 years.

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Question 39 Exercise 2.2

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Answer:

Solution:

Let Ravi’s present age be x years.

After fifteen years, Ravi’s age = 4x years.

Fifteen years from now, Ravi’s age = (x+15) years.

According to question, 4x = x + 15

\Rightarrow\ 4x-x=15

[Transposing x to L.H.S]

3x = 15

\Rightarrow\ \frac{3x}{3}=\frac{15}{3}

[Dividing both sides by 3]

x = 5 years.

Hence, Ravi’s present age be 5 years.

Video transcript

"Dear students, let's understand the question 15 years from now ravi's age will be 4 times is present age. What is love he's present age in this some we don't know his age. Whenever we don't know the value of something we use as a recognition. That means we use letters from English alphabets like XYZ as a variable. So you're in this somehow, let's taik rubbish present 8px years. So let's write down let Robbie's present age the exhales. So 15 years from now. He's it will become he's got a date alexios 15 years later. So in mockery later means addition so is eight would be X plus 50. Now according to the second statement is the bees 8 will be four times his presentation fo X means for X is presented. So wh will become four times that means phone in to present data is X so for X now according to the problem 15 years from now. Wh so let us first take this statement 15 years from now 15 years from now. Wh that means 15 years from now. Our visit is how much X plus 15. So let me write first. Let us write first. Second statement fo X is present age. Fo X is present age that means buildi means is equal to so let us write the equal to 4 times is present is that we have taken as 4 x so our linear equation is X plus 15 is equal to four x now, we will use transpose method in transpose method. There are talks like the LHS and rhs left hand side and right hand side. So whenever you're solving a soft, we always keep the variables or the algebraic expression on the left-hand side. And the constant that is the number on the right hand side. Also, we need to remember whenever we are changing the left-hand side to the right-hand side. We need to remember integers room. So as for the integers rule This is minus minus plus plus minus minus minus plus minus and plus plus plus so we also need to remember whenever we are transposing the numbers on the right hand side the sign changes. That means this is the minus will become Plus or plus will become - so let's look at some let's first open the bracket X plus 15 is equal to 4X. So as I said earlier, we need to take as a big education or the left hand side. So you could be heads and your this point will come on the left-hand side. Here. It is plus when it comes on the left side, it becomes - so you're going to write. X minus 4X is equal to we are going to take the constant rate is the number on the right hand side when it comes on the right hand side. This is plus when it comes on the right hand side will become - so you're going to write minus 15. Now. Let's solve for S is 1 x 1 x minus four x over 1 minus 4 will be minus 3 and why have I done - three whenever we do a teacher's role. That is your it is plus minus. It will become minus what we will use the greater number sign. So the way the numbers on your is - when the result it would always be minus. So minus D. There is my answer would be minus 3, so let's write down so it would - the x is equal to minus 50 now again, you're going to use transpose method here on the left hand side. The algebraic expression is minus 3 x that means minus 3 multiplied by X. Whenever the constant terms on the right hand side when it is Multiplied. It will become divided. So you will get X your again remember today right right hand side first. Let me see what you like - 51st and as I said earlier your or the left inside it was multiplied when it comes on the right hand side it becomes 2y so it would be minus 15 divided by -3. So when we solve this, let's divide minus 15 divided by -3, so Demons are three fives are 15 and the - - - cancel. So it would be plus 5. So the answer would be X is equal to 5. So as we had taken Robbie's present a tech CEOs, so that means the dog is present 8 is 5 years. So let's write down the code. So therefore the bees present age will be the bees present age is We have completed the some. Thank you."

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