Answer :
Given:
The equation is
[tex]-\dfrac{1}{4}d-\dfrac{2}{5}d=39[/tex]
To find:
The value of d.
Solution:
We have,
[tex]-\dfrac{1}{4}d-\dfrac{2}{5}d=39[/tex]
Taking LCM, we get
[tex]\dfrac{-5d-8d}{20}=39[/tex]
[tex]\dfrac{-13d}{20}=39[/tex]
Multiply both sides by 20.
[tex]-13d=39\times 20[/tex]
Divide both sides by -13.
[tex]d=\dfrac{39\times 20}{-13}[/tex]
[tex]d=-3\times 20[/tex]
[tex]d=-60[/tex]
Therefore, the value of d is -60.