To find this answer, you would need to find how many miles 1 gallon of gas will take them. To find this, you would do 290÷8=36.25. So with this information, you will be able to find out how much gas it would take to travel 400 miles. You would do 400÷36.25=11.03. 11.03 would be how many gallons of gas is used to travel 400 miles. Hope this helps! ;)
Answer:

Step-by-step explanation:
40ab is 40 multiplied by a multiplied by b
0.03x+0.06 (6500-x)=225
Solve for x
0.03x+390-0.06x=225
0.03x-0.06x=225-390
-0.03x=-165
X=165÷0.03
X=5500 invested at 3%
6500-5500=1000 invested at 6%