The independent variable is is the price per bag.
By pythagoras Theorem.
x² +12²=13²
=>x² +144 =169
=>x² =169-144=25
=>x=√25=5 unit.
Hence x=5 is your answer.
Hope it helps...
Regards,
Leukonov/Olegion.
280 eels
92 + 56 + 52 = 200
eel = 56/200
56 *5 x
----- = --------
200 *5 1000
56(5) = 280 x = 280
56/200 = 7/25
7/25 = 280/1000
-3(6-10v-5v)
=-3(6-15v)
=-18+45v
-18+45v is the final answer.