Answer:
The small box contains 21 cans
Step-by-step explanation:
Represent the small box with S and the large with L.
For Estelle:
[tex]3L + 5S = 170[/tex]
For the boy:
[tex]4L + 4S = 184[/tex]
Required
Determine the cans in the small box
[tex]3L + 5S = 170[/tex] --- (1)
[tex]4L + 4S = 184[/tex] --- (2)
Divide (2) through by 4
[tex]L + S = 46[/tex]
Make L the subject
[tex]L = 46 -S[/tex]
Substitute 46 - S for L in (1)
[tex]3L + 5S = 170[/tex]
[tex]3(46 - S) + 5S = 170[/tex]
Open bracket
[tex]128 - 3S + 5S = 170[/tex]
[tex]128 + 2S = 170[/tex]
Collect Like Terms
[tex]2S = 170-128[/tex]
[tex]2S = 42[/tex]
Divide both sides by 2
[tex]S = 21[/tex]
Hence, the small box contains 21 cans