# Solving by Substitution Story Problem help

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• March 9th 2009, 12:46 PM
Firefightinfool
Solving by Substitution Story Problem help
An airplane has a total of 152 seats. The number of coach-class seats is 5 more than six times the number of first-class seats. How many of each type of seat are there on the plane?

After hours of algebra homework, my brain seems fried! This is suppose to be solved using substition. Can anybody help me with this? Once I see how, Im sure I'll say duuhhhh.

THank You in advance!!
Todd
• March 9th 2009, 12:53 PM
earboth
Quote:

Originally Posted by Firefightinfool
An airplane has a total of 152 seats. The number of coach-class seats is 5 more than six times the number of first-class seats. How many of each type of seat are there on the plane?

After hours of algebra homework, my brain seems fried! This is suppose to be solved using substition. Can anybody help me with this? Once I see how, Im sure I'll say duuhhhh.

THank You in advance!!
Todd

Let x denote the number of first-class-seats and y the number of the coach-class-seats. Then you know:

$x + y = 152$ and $y = 6x+5$

Substitute y by the RHS of the second equation:

$x + 6x+5=152~\implies~7x=147~\implies~x=21$
• March 9th 2009, 12:54 PM
masters
Quote:

Originally Posted by Firefightinfool
An airplane has a total of 152 seats. The number of coach-class seats is 5 more than six times the number of first-class seats. How many of each type of seat are there on the plane?

After hours of algebra homework, my brain seems fried! This is suppose to be solved using substition. Can anybody help me with this? Once I see how, Im sure I'll say duuhhhh.

THank You in advance!!
Todd

Hi Firefightinfool,

And using the non-substitution method...

Let x = number of 1st class seats

Let 6x + 5 = number of coach class seats

x + 6x + 5 = 152

Solve for x to get the number of 1st class seats.

Solve for 6x + 5 to get the number of coach class seats.