One solution
Step-by-step explanation:
0.75 (x + 40) = 0.35 (x + 20) + 0.35 (x + 20)
0.75x + 30 = 0.35x + 7 + 0.35x + 7
0.75x + 30 = 0.7x + 14
0.05x + 30 = 14
0.05x = -16
x = -320
Hope this helps!