Respuesta :
The cost of one pack of coffee is $12 and cost of one tea pack is $6.
Step-by-step explanation:
Let,
Cost of one pack of coffee = x
Cost of one pack of tea = y
According to given statement;
39x+45y=738 Eqn 1
11x+13y=210 Eqn 2
Multiplying Eqn 1 by 11
[tex]11(39x+45y=738)\\429x+495y=8118\ \ \ Eqn\ 3\\[/tex]
Multiplying Eqb 2 by 39
[tex]39(11x+13y=210)\\429x+507y=8190\ \ \ Eqn\ 4[/tex]
Subtracting Eqn 3 from Eqn 4
[tex](429x+507y)-(429x+495y)=8190-8118\\429x+507y-429x-495y=72\\12y=72[/tex]
Dividing both sides by 12
[tex]\frac{12y}{12}=\frac{72}{12}\\y=6[/tex]
Putting y=6 in Eqn 2
[tex]11x+13(6)=210\\11x+78=210\\11x=210-78\\11x=132[/tex]
Dividing both sides by 11
[tex]\frac{11x}{11}=\frac{132}{11}\\x=12[/tex]
The cost of one pack of coffee is $12 and cost of one tea pack is $6.
Keywords: linear equation, subtraction
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Answer:
A pack of coffee=$12
A pack of tea=$6
Step-by-step explanation:
Let the cost of 1 pack of coffee =c
and the cost of 1 pack of tea =t
we can the write the following equations
39c+45t=738...........eqn(1)
11c+13t=738...........eqn(2)
Multiply eqn(1) by 11
429c+495t=8118...........eqn(3)
Multiply eqn(2) by 39
429c+507t=8190...........eqn(4)
eqn(4)-eqn(3)
This implies
12t=72
Dividing through by 12 ,we get
t=6
substituting the value of t into equation two,we obtain
11c+13(6)=210
11c+78=210
11c=210-78
11c=132
Dividing through by 11,we obtain
c=12