0.8(x+4) + 0.5(x+9) = 9

Simplify the equation:

0.8x + 3.2 + 0.5x + 4.5 = 9

Combine like terms:

1.3x + 7.7 = 9

Subtract 7.7 from both sides:

1.3x = 1.3

Divide by 1.3:

x = 1

Therefore, the solution to the equation is x = 1.