A flower shop sells tulips and roses. The price of each tulip is the same, and the price of each rose is the same. One customer bought 7 tulips and 9 roses for $25.90. Another customer bought 4 tulips and 8 roses for $19.80. How much will it cost a customer to buy 5 tulips and 6 roses?

Respuesta :

It will cost a customer $17.75 to buy 5 tulips and 6 roses.

Step-by-step explanation:

Let,

Cost of one tulip = x

Cost of one rose = y

According to given statement;

7x+9y=25.90       Eqn 1

4x+8y=19.80       Eqn 2

Multiplying Eqn 1 by 4

[tex]4(7x+9y=25.90)\\28x+36y=103.60\ \ \ Eqn\ 3[/tex]

Multiplying Eqn 2 by 7

[tex]7(4x+8y=19.80)\\28x+56y=138.60\ \ \ Eqn\ 4\\[/tex]

Subtracting Eqn 3 from Eqn 4

[tex](28x+56y)-(28x+36y)=138.60-103.60\\28x+56y-28x-36y=35\\20y=35[/tex]

Dividing both sides by 20

[tex]\frac{20y}{20}=\frac{35}{20}\\y=1.75[/tex]

Putting y=1.75 in Eqn 1

[tex]7x+9(1.75)=25.90\\7x+15.75=25.90\\7x=25.90-15.75\\7x=10.15[/tex]

Dividing both sides by 7

[tex]\frac{7x}{7}=\frac{10.15}{7}\\x=1.45[/tex]

Cost of 5 tulips and 6 roses = 5x+6y = 5(1.45)+6(1.75) = 7.25+10.50 = $17.75

It will cost a customer $17.75 to buy 5 tulips and 6 roses.

Keywords: linear equation, elimination method

Learn more about elimination method at:

  • brainly.com/question/11150876
  • brainly.com/question/11175936

#LearnwithBrainly

You can use system of linear equations to find the solution.

The  cost to customer to buy 5 tulips and 6 roses will be $17.75

Given that:

  • The price of all tulips are same.
  • The price of all roses are same.
  • Price of 7 tulips and 9 roses is $25.90
  • Price of 4 tulips and 8 roses is $19.80

To find:

Cost of buying 5 tulips and 6 roses.

Naming the prices:

  • Let price of one tulip be $x
  • Let price of one rose be $y

Forming system of equations:

By given data, we have:

7 tulip + 9 roses costs $25.90

or

[tex]7x + 9y = 25.9[/tex]

And

4 tulips + 8 roses costs $19.8

or

[tex]4x + 8y = 19.8[/tex]

Thus, we have two equations.

Using method of substitution:

From equation first, we have:

[tex]7x + 9y = 25.9\\\\ x = \dfrac{25.9-9y}{7} [/tex]

Substituting this value in second equation, we get:

[tex]4(\dfrac{25.9 - 9y}{7}) + 8y = 19.8\\\\ 103.6 - 36y + 56y = 138.6\\ 20y = 138.6 - 103.6\\\\ y = \dfrac{35}{20} = 1.75\\ [/tex]

Thus, we have:

[tex]x = \dfrac{25.9-9y}{7} \\ \\ x = \dfrac{25.9 - 15.75}{7} = 1.45[/tex]

Thus, the price of a tulip = x = $1.45

and the price of a rose = y = $1.75

Now, calculating price of 5 tulips and 6 roses:

[tex]\: \rm Total \: Cost = 5x + 6y = 5 \times 1.45 + 6 \times 1.75 = \$17.75[/tex]

Thus, the cost to a customer who buys 5 tulips and 6 roses would be $17.75

Learn more about system of linear equations here:

https://brainly.com/question/13827324