2(1d-21)=7d-78

Solution for 2(1d-21)=7d-78 equation:

Simplifying
2(1d + -21) = 7d + -78

Reorder the terms:
2(-21 + 1d) = 7d + -78
(-21 * 2 + 1d * 2) = 7d + -78
(-42 + 2d) = 7d + -78

Reorder the terms:
-42 + 2d = -78 + 7d

Solving
-42 + 2d = -78 + 7d

Solving for variable 'd'.

Move all terms containing d to the left, all other terms to the right.

Add '-7d' to each side of the equation.
-42 + 2d + -7d = -78 + 7d + -7d

Combine like terms: 2d + -7d = -5d
-42 + -5d = -78 + 7d + -7d

Combine like terms: 7d + -7d = 0
-42 + -5d = -78 + 0
-42 + -5d = -78

Add '42' to each side of the equation.
-42 + 42 + -5d = -78 + 42

Combine like terms: -42 + 42 = 0
0 + -5d = -78 + 42
-5d = -78 + 42

Combine like terms: -78 + 42 = -36
-5d = -36

Divide each side by '-5'.
d = 7.2

Simplifying
d = 7.2