4x+8x+12x+16x=5+10+30+40
4x+8x+12x+16x= 85
40x=85
x= 85/40
x=2.125
Answer: D. 3 x 10^7
Step-by-step explanation: 9.6/3.2=3 and 10^9/10^2 is 9-2=7, so 10^7, so it would be 3 x 10^7.