Answer:
large box weights 40 pounds & small box weights 35 pounds
Explanation:
We can write 2 equations and solve simultaneous.
Let x be weight of large box and y be weight of small box
"The combined weight of a large box and a small box is 75 pounds.":
![x+y=75](https://img.qammunity.org/2020/formulas/mathematics/college/iqqbljejl6jfp1n28b7zlccb2saj9o9gn4.png)
"The truck is transporting 70 large boxes and 65 small boxes. If the truck is carrying a total of 5075 pounds":
![70x+65y=5075](https://img.qammunity.org/2020/formulas/mathematics/college/6u4ctputago3eyukqgh5kdkjzhj3mhxbfe.png)
Now we can solve for x in the first equation, which is x = 75 -y
We now substitute this into the 2nd equation and solve for y:
![70x+65y=5075\\70(75-y)+65y=5075\\5250-70y+65y=5075\\-5y=5075-5250\\-5y=-175\\y=35](https://img.qammunity.org/2020/formulas/mathematics/college/iluffxbrlwbof0d2k50yxvtzpcujut777p.png)
Using y = 35 and plugging that into the 1st equation, we can solve for x:
![x+y=75\\x+35= 75\\x= 75 - 35\\x=40](https://img.qammunity.org/2020/formulas/mathematics/college/rs5be6zz05z4vngao76lg9cchad2t7irdf.png)
Hence, large box weights 40 pounds & small box weights 35 pounds