Solve the given linear equation $\dfrac{{x + 6}}{4} - \dfrac{{5x - 4}}{8} + \dfrac{{x - 3}}{5} = 0$
Answer
627.3k+ views
Hint: Here, we will first take the LCM of the denominators and solve the numerator to form a linear equation with one variable. Solving further, we will be able to find the required value of $x$ which will be our required answer.
Complete step-by-step answer:
In order to solve $\dfrac{{x + 6}}{4} - \dfrac{{5x - 4}}{8} + \dfrac{{x - 3}}{5} = 0$
First of all, we will find out the LCM of the denominators.
As we can see in the denominator we have the numbers 4, 8 and 5.
Hence, in 4 and 8 (as they are common factors), 8 is the LCM.
Thus, we will find the LCM of 8 and 5 where there is no common factor and we will have to multiply both of them to find the LCM.
Therefore, LCM $ = 8 \times 5 = 40$
Hence, LCM of the denominators 4, 8 and 5 is 40.
Now, for the first fraction, in order to make the denominator 40, we will multiply both the numerator as well as the denominator by 10
Similarly, for the second fraction, in order to make the denominator 40, we will multiply both the numerator as well as the denominator by 5
Also, for the third fraction, in order to make the denominator 40, we will multiply both the numerator as well as the denominator by 8
Thus, we get,
$\dfrac{{10\left( {x + 6} \right) - 5\left( {5x - 4} \right) + 8\left( {x - 3} \right)}}{{40}} = 0$
Multiplying both side by 40, we get
$ \Rightarrow 10x + 60 - 25x + 20 + 8x - 24 = 0$
Adding the like terms, we get
$ \Rightarrow - 7x + 56 = 0$
Adding 56 on both sides, we get
$ \Rightarrow 7x = 56$
Dividing both sides by 7, we get
$ \Rightarrow x = 8$
Therefore, the value of $x$ is 8.
Hence, this is the required answer.
Note: We can also check whether our answer is correct or not by substituting the value of $x$ in the given question.
Thus, it is given that:
$\dfrac{{x + 6}}{4} - \dfrac{{5x - 4}}{8} + \dfrac{{x - 3}}{5} = 0$
Here, substituting $x = 8$, we get,
LHS $ = \dfrac{{8 + 6}}{4} - \dfrac{{5\left( 8 \right) - 4}}{8} + \dfrac{{8 - 3}}{5}$
$ \Rightarrow $ LHS $ = \dfrac{{14}}{4} - \dfrac{{36}}{8} + \dfrac{5}{5}$
Solving further,
$ \Rightarrow $ LHS $ = \dfrac{7}{2} - \dfrac{9}{2} + 1$
$ \Rightarrow $ LHS $ = \dfrac{{7 - 9}}{2} + 1$
Now, solving further, we get,
$ \Rightarrow $ LHS $ = \dfrac{{ - 2}}{2} + 1 = - 1 + 1 = 0$
Clearly, LHS $ = $ RHS
Therefore, our answer is correct.
Hence, the required value of $x$ is 8.
Thus, this is the required answer.
Complete step-by-step answer:
In order to solve $\dfrac{{x + 6}}{4} - \dfrac{{5x - 4}}{8} + \dfrac{{x - 3}}{5} = 0$
First of all, we will find out the LCM of the denominators.
As we can see in the denominator we have the numbers 4, 8 and 5.
Hence, in 4 and 8 (as they are common factors), 8 is the LCM.
Thus, we will find the LCM of 8 and 5 where there is no common factor and we will have to multiply both of them to find the LCM.
Therefore, LCM $ = 8 \times 5 = 40$
Hence, LCM of the denominators 4, 8 and 5 is 40.
Now, for the first fraction, in order to make the denominator 40, we will multiply both the numerator as well as the denominator by 10
Similarly, for the second fraction, in order to make the denominator 40, we will multiply both the numerator as well as the denominator by 5
Also, for the third fraction, in order to make the denominator 40, we will multiply both the numerator as well as the denominator by 8
Thus, we get,
$\dfrac{{10\left( {x + 6} \right) - 5\left( {5x - 4} \right) + 8\left( {x - 3} \right)}}{{40}} = 0$
Multiplying both side by 40, we get
$ \Rightarrow 10x + 60 - 25x + 20 + 8x - 24 = 0$
Adding the like terms, we get
$ \Rightarrow - 7x + 56 = 0$
Adding 56 on both sides, we get
$ \Rightarrow 7x = 56$
Dividing both sides by 7, we get
$ \Rightarrow x = 8$
Therefore, the value of $x$ is 8.
Hence, this is the required answer.
Note: We can also check whether our answer is correct or not by substituting the value of $x$ in the given question.
Thus, it is given that:
$\dfrac{{x + 6}}{4} - \dfrac{{5x - 4}}{8} + \dfrac{{x - 3}}{5} = 0$
Here, substituting $x = 8$, we get,
LHS $ = \dfrac{{8 + 6}}{4} - \dfrac{{5\left( 8 \right) - 4}}{8} + \dfrac{{8 - 3}}{5}$
$ \Rightarrow $ LHS $ = \dfrac{{14}}{4} - \dfrac{{36}}{8} + \dfrac{5}{5}$
Solving further,
$ \Rightarrow $ LHS $ = \dfrac{7}{2} - \dfrac{9}{2} + 1$
$ \Rightarrow $ LHS $ = \dfrac{{7 - 9}}{2} + 1$
Now, solving further, we get,
$ \Rightarrow $ LHS $ = \dfrac{{ - 2}}{2} + 1 = - 1 + 1 = 0$
Clearly, LHS $ = $ RHS
Therefore, our answer is correct.
Hence, the required value of $x$ is 8.
Thus, this is the required answer.
Recently Updated Pages
You are the head boyhead girl Write a notice informing class 7 english CBSE

The image formed by a plane mirror is always laterally class 7 physics CBSE

When phenolphthalein is added toNaOH the colour of class 7 chemistry CBSE

Find the least number which when divided by 15 leaves class 7 maths CBSE

Show that one and only one out of n n + 2n or n + -class-7-maths-CBSE

During heavy exercise we get cramps in the legs due class 7 biology CBSE

Trending doubts
Full Form of IASDMIPSIFSIRSPOLICE class 7 social science CBSE

List of coprime numbers from 1 to 100 class 7 maths CBSE

The plural of Chief is Chieves A True B False class 7 english CBSE

Collective noun a of sailors class 7 english CBSE

Write a short note on the great bath of MohenjoDar class 7 social science CBSE

What three things did Gopal do before going to buy class 7 english CBSE


