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Linear Equations in One Variable | Exercise 2.4

Question 3

Q2) A positive number is 5 times another number. If 21 is added to both the numbers, then one of the new numbers becomes twice the other new number. What are the numbers?

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  • Solution

  • Transcript

Solution:

Let another number be x.

Then positive number = 5x

According to the question, 5x+21=2\left(x+21\right)

\Rightarrow5x+21=2x+42

\Rightarrow5x-2x=42-21

\Rightarrow3x=21

\Rightarrow x=\frac{21}{3}=7

Hence another number = 7 and positive number = 7 x 5 = 35.

hello kids welcome to Lido homework the question we are going to solve today is this word problem it states a positive number is 5 times another number if 21 is added to both the numbers then 1 of the new number becomes twice the other new number what are the numbers the word numbers makes it a little confusing and the multiple use of numbers so let's break this question down let's look at the first sentence a positive number is five times another number so the relation is that this, whatever this positive number is, is five times another number so let's take that to another number where it mentions another number equal to x so the positive number like stated in the question is this positive number is nothing but five times of another number that is x great now the second part of the question is if 21 is added to both the numbers let's first do this adding 21 to both numbers what do we get the first number that is x becomes x plus 21 the second number over here or the positive number becomes 5x plus 21 great now go back to the question and it says if 21 is added to both the numbers which we have over here then one of the new numbers becomes twice the other new number which is the new number here the one I'm boxing over here after adding 21 these are your new numbers go back to the question and it says one of the new numbers let's take for example 5 x plus 21 one of the new number becomes twice the other new number twice is 2 times the other new number is x plus 21 there you go we've got our equation and now let's solve this so over here I Can see a bracket so let's take the 2 inside the bracket let's keep the left-hand side as it is for now and then 2 goes inside the bracket it is 2 into x is 2 x plus 2 into 21 is 42 right now let's shuffle the terms and get all the x terms on one side so 2x comes on the left-hand side it becomes minus 2x is equal to 42 this 21 comes on the right-hand side becomes minus 21. 5x minus 2x is 3x 42 minus 21 is 21. We need to find the value of x right so this 3 needs to shift this side and when it comes on this side; it becomes a division right, and this goes in the three stable by seven so x equal to seven so another number that this what problem states is nothing but seven leave any doubts or comments you have in the comments section and we'll try to get back to you that's all from this video thank you

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Question 3

Q2) A positive number is 5 times another number. If 21 is added to both the numbers, then one of the new numbers becomes twice the other new number. What are the numbers?

  • Solution

  • Transcript

Solution:

Let another number be x.

Then positive number = 5x

According to the question, 5x+21=2\left(x+21\right)

\Rightarrow5x+21=2x+42

\Rightarrow5x-2x=42-21

\Rightarrow3x=21

\Rightarrow x=\frac{21}{3}=7

Hence another number = 7 and positive number = 7 x 5 = 35.

hello kids welcome to Lido homework the question we are going to solve today is this word problem it states a positive number is 5 times another number if 21 is added to both the numbers then 1 of the new number becomes twice the other new number what are the numbers the word numbers makes it a little confusing and the multiple use of numbers so let's break this question down let's look at the first sentence a positive number is five times another number so the relation is that this, whatever this positive number is, is five times another number so let's take that to another number where it mentions another number equal to x so the positive number like stated in the question is this positive number is nothing but five times of another number that is x great now the second part of the question is if 21 is added to both the numbers let's first do this adding 21 to both numbers what do we get the first number that is x becomes x plus 21 the second number over here or the positive number becomes 5x plus 21 great now go back to the question and it says if 21 is added to both the numbers which we have over here then one of the new numbers becomes twice the other new number which is the new number here the one I'm boxing over here after adding 21 these are your new numbers go back to the question and it says one of the new numbers let's take for example 5 x plus 21 one of the new number becomes twice the other new number twice is 2 times the other new number is x plus 21 there you go we've got our equation and now let's solve this so over here I Can see a bracket so let's take the 2 inside the bracket let's keep the left-hand side as it is for now and then 2 goes inside the bracket it is 2 into x is 2 x plus 2 into 21 is 42 right now let's shuffle the terms and get all the x terms on one side so 2x comes on the left-hand side it becomes minus 2x is equal to 42 this 21 comes on the right-hand side becomes minus 21. 5x minus 2x is 3x 42 minus 21 is 21. We need to find the value of x right so this 3 needs to shift this side and when it comes on this side; it becomes a division right, and this goes in the three stable by seven so x equal to seven so another number that this what problem states is nothing but seven leave any doubts or comments you have in the comments section and we'll try to get back to you that's all from this video thank you

Our top 5% students will be awarded a special scholarship to Lido.

subject-cta
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