Question 180802
LET X BE THE NUMBER OF $0.34 STAMPS
LET Y BE THE NUMBER OF $0.23 STAMPS

SYSTEM OF LINEAR EQUATIONS

a) ($0.34)X + ($0.23)Y = $4.44
b)        X +        Y = 15


SOLVING
a)  (0.34)X + (0.23)Y =  4.44
b) (-0.34)X - (0.34)Y = -5.10 <---- MULTIPLY BY -0.34 TO ELIMINATE X

YOU WILL GET A NEW EQUATION
c) -0.11Y = -0.66

IF YOU SOLVE FOR Y, THEN YOU WILL GET Y= 6
TO FIND X YOU TAKE THE VALUE OF Y AND SUSTITUTE IN THE ORIGINAL EQUATION
b) X + Y = 15, ---> X + 6 = 15;  THEN X = 9


THE ANSWER WILL BE:
9 STAMPS OF $0.34, AND 6 STAMPS OF $0.23 WERE SOLD