Let the cost of one lemon meringue pie be $M.
Let the cost of one blueberry pie be $B.
Two lemon meringue pies cost $3 less than 4 blueberry pies .
4B-2M=3 .............................equation 1
Three lemon meringue pies cost $9 more than 3 blueberry pies .
3M-3B=9 ...................................equation 2
Multipl eq1 by 3 and eq 2 by2 we get
12B-6M=9
6M-6B=18
Adding the above 2 eqs we get
6B=27
B=27/6=4.5
substituting for B in eq2 we get
3M-3(4.5)=9
3M-13.5=9
3M=9+13.5
3M=22.5
M=22.5/3=7.5
Cost of one lemon meringue pie is $7.5 and that of one blueberry pie is $4.5