To solve this equation, we need to isolate the variable x.
First, let's distribute 2/5 to both terms inside the parentheses:
(2/5)(10x + 15) = 26
(2/5)(10x) + (2/5)(15) = 26
(4x/5) + (6/5) = 26
Now, let's combine like terms:
4x/5 + 6/5 = 26
Next, let's get rid of the fractions by multiplying both sides of the equation by 5:
5(4x/5 + 6/5) = 5(26)
4x + 6 = 130
Now, let's isolate the variable x by subtracting 6 from both sides of the equation:
4x + 6 - 6 = 130 - 6
4x = 124
To solve for x, divide both sides of the equation by 4:
4x/4 = 124/4
x = 31
Therefore, the solution to the equation is x = 31.