Answer:
Small box weighs 13.75 kg & large box weighs 15.75 kg
Step-by-step explanation:
We can write 2 simultaneous equation and solve for weight of each box.
Let weight of large box be l and small box be s.
"3 large boxes and 5 small boxes has a total weight of 116 kilograms":
[tex]3l+5s=116[/tex]
and
"9 large boxes and 7 small boxes has a total weight of 238 kilograms":
[tex]9l+7s=238[/tex]
Now we can solve for l in the 1st equation and put it into 2nd equation and get s:
[tex]3l+5s=116\\3l=116-5s\\l=\frac{116-5s}{3}[/tex]
now,
[tex]9l+7s=238\\9(\frac{116-5s}{3})+7s=238\\3(116-5s)+7s=238\\348-15s+7s=238\\348-238=15s-7s\\110=8s\\s=\frac{110}{8}=13.75[/tex]
now we plug in 13.75 into s into equation of l to find s:
[tex]l=\frac{116-5s}{3}\\l=\frac{116-5(13.75)}{3}\\l=15.75[/tex]