Answer:
a). 8=b+s.....equation 1
9=p+s.....equation 2
13.5=b+p+s.....equation 3
b). The cost of pizza,p=$5.5
The cost of burger,b=$4.5
The cost of soda, s=$3.5
Step-by-step explanation:
a). The equations for the total amount spent by each individual are as follows;
Total amount Louis used=Burger cost+Soda cost
Let Burger cost=b,
Soda cost=s
Replacing;
8=b+s.....equation 1
Total amount Kate used=Pizza cost+Soda cost
Let Pizza cost=p,
Soda cost=s
Replacing;
9=p+s.....equation 2
Total amount David used=Burger cost+Pizza cost+Soda cost
Let Pizza cost=p,
Soda cost=s
Burger cost=b
Replacing;
13.5=b+p+s.....equation 3
All the equations are as follows;
8=b+s.....equation 1
9=p+s.....equation 2
13.5=b+p+s.....equation 3
b).Replace the value of p+s in equation 3 with 8 from equation 1;
13.5=b+9
b=13.5-9=4.5, b=4.5
Replace value of b in equation 1 with 4.5;
8=4.5+s
s=8-4.5=3.5, s=3.5
Re[lace values of b and s in equation 3 with 4.5 and 3.5 respectively'
13.5=4.5+p+3.5
13.5=p+8
p=13.5-8=5.5, p=5.5
The cost of pizza,p=$5.5
The cost of burger,b=$4.5
The cost of soda, s=$3.5
