Elle went to Pet Smart and bought 4 goldfish and 3 turtles for $28. Later that day, Warren went to Pet Smart and bought 6 goldfish and 1 turtle for $10. How much does 1 goldfish cost?

1 Answer
Nallasivam V
Oct 7, 2015

Price of gold fish $#1/7#

Explanation:

Let #g# be the price of goldfish
Let #t# bt the price of turtles
Then -
#4g+3t=28# ----------------(1)
#6g+1t=10#------------------(2)

Solve the 1st equation for #t#
#t=10-6g#
#4g+3(10-6g)=28#
#4g+30-18g=28#
#-14g=28-30=-2#
#g=(-2)/(-14)=1/7#
Price of gold fish $#1/7#

This is optional. This is not asked in the prolem
Substitute the value #g=1/7# in equation (2)

#4(1/7)+3t=28#
#4+21t=196#
#21t=196-4=192#
#t=192/21#

Price of one turtle $ #192/21#

Related questions
See all questions in Systems Using Substitution
Impact of this question
2154 views around the world
You can reuse this answer
Creative Commons License