Posted by ellis on .
find the solution of each equation if the replacement sets are x:{1,3,5,7,9} and y:{2,4,6,8,10}.
3x9=12
y^25y11=13

math exam tommrow review 
Reiny,
3x9=12
3x = 12+9
3x = 21
x = 7 , which is a member of your solution set
y^2  5y  11 = 13
y^2  5y  24  0
(y8)(x+3) = 0
y = 8 or y = 3
only y=8 is a solution, since 3 is not part of your solution set. 
math exam tommrow review 
ellis,
so i don't have to plug in each number?

math exam tommrow review 
Reiny,
yes, you could do that.
I don't know what grade level you are at.
The second question involved solving a quadratic.
If you don't know what that is, then plugging in each value of the replacement set would be your way of doing it.