For the total pounds of the truck to be 4900 pounds
large = 40 pounds
small = 35 pounds
to see that this answer is correct
40x70=2800
35x60=2100
+=4900
What are you asking to solve?
First, use distributive property on the right half.
2 * 5 = 10
2 * 2n = 4n
4n - 9 = 10 + 4n
Add 9 to both sides
4n = 19 + 4n
Subtract 4n from both sides
0 = 19
But thats not true. Therefore, there is no solution.