Final answer:
The equation 40 = 3x + (5x - 10) simplifies to 40 = 8x - 10. After rearranging and solving for x, we find that x = 6.25.
Step-by-step explanation:
To find x in the equation, we should first combine like terms. The equation given is 40 = 3x + (5x - 10). Combining like terms (3x and 5x) on the right side, we get 40 = 8x - 10. We then isolate the variable x by adding 10 to both sides of the equation, which gives us 50 = 8x. Finally, we divide both sides by 8 to solve for x, resulting in x = 6.25.