3(1-7k)+7(k-6)=45

Solution for 3(1-7k)+7(k-6)=45 equation:

Simplifying
3(1 + -7k) + 7(k + -6) = 45
(1 * 3 + -7k * 3) + 7(k + -6) = 45
(3 + -21k) + 7(k + -6) = 45

Reorder the terms:
3 + -21k + 7(-6 + k) = 45
3 + -21k + (-6 * 7 + k * 7) = 45
3 + -21k + (-42 + 7k) = 45

Reorder the terms:
3 + -42 + -21k + 7k = 45

Combine like terms: 3 + -42 = -39
-39 + -21k + 7k = 45

Combine like terms: -21k + 7k = -14k
-39 + -14k = 45

Solving
-39 + -14k = 45

Solving for variable 'k'.

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

Add '39' to each side of the equation.
-39 + 39 + -14k = 45 + 39

Combine like terms: -39 + 39 = 0
0 + -14k = 45 + 39
-14k = 45 + 39

Combine like terms: 45 + 39 = 84
-14k = 84

Divide each side by '-14'.
k = -6

Simplifying
k = -6