Question

2.1d+18=2.16(d+8)

Answer 1

If you are solving for d, you must first distribute the right side of the equation. Then you will have:
2.1d+ 18 = 2.16d + 17.28

Subtract both sides by 18 to leave the d term by itself on the left side of the equation. Then you will have:
2.1d = 2.16d - .76

Subtract both sides by 2.16d so you have d terms together on the left and the other term on the right. Then you will have:
-0.06d = - .76

You can make this equation positive by multiplying both sides by -1.
0.06d = .76

Lastly, divide both sides by 0.06 to determine what d is equal to.

d = 12.666666666666666666666666666667
or
d = 12 and 2/3