-3+2(1+4r)=18

Solution for -3+2(1+4r)=18 equation:

Simplifying
-3 + 2(1 + 4r) = 18
-3 + (1 * 2 + 4r * 2) = 18
-3 + (2 + 8r) = 18

Combine like terms: -3 + 2 = -1
-1 + 8r = 18

Solving
-1 + 8r = 18

Solving for variable 'r'.

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

Add '1' to each side of the equation.
-1 + 1 + 8r = 18 + 1

Combine like terms: -1 + 1 = 0
0 + 8r = 18 + 1
8r = 18 + 1

Combine like terms: 18 + 1 = 19
8r = 19

Divide each side by '8'.
r = 2.375

Simplifying
r = 2.375