Answer:
[tex] \boxed{ \boxed{ \bold{ \sf{d = 15}}}}[/tex]
Step-by-step explanation:
[tex] \sf{d - 7 = 8}[/tex]
Move constant to right hand side and change it's sign
⇒[tex] \sf{d = 8 + 7}[/tex]
Add the numbers
⇒[tex] \sf{d = 15}[/tex]
Let's check:
When d = 15 , R.H.S = 15 - 7 = 8
And L.H.S = 8
Thus , R.H.S = L.H.S when d = 15.
Therefore d = 15 is the solution of the equation.
Hope I helped!
Best regards!