Answer:C
Explanation:
Let x represent the cost of a bouquet of tulips.
Let y represent the cost of a bouquet of roses.
Let z represent the cost of a bouquet of lilies.
Jessica ordered 10 bouquets of tulips, 4 bouquets of roses, and 6 bouquets of lilies for a total of $670. This means that
10x + 4y + 6z = 670 - - - - - - - - - 1
The combined cost to buy one of each type of bouquet is $115. This means that
x + y + z = 115- - - - - - - - - 2
If a bouquet of lilies costs $5 more than a bouquet of tulips, it means that
z = x + 5 - - - - - - - - - 3
Substituting equation 3 into equation 1 and equation 2, it becomes
10x + 4y + 6(x+5)= 670
10x +4y + 6x + 30 = 670
16x + 4y = 670 - 30
16x + 4y = 640 = - - - - - - - - - 4
Substituting equation 3 into equation 2, it becomes
x + y + x + 5 =
2x + y = 115 - 5
2x + y = 110 - - - - - - - - - 5
Multiplying equation 5 by 4 , it becomes
8x + 4y = 440 - - - - - - - - - 6
Subtracting equation 6 from equation 4, it becomes
8x = 200
x = 200/8 = 25
2x + y = 110
2×25 + y = 110
50 + y = 110
y = 110 - 50 = 60
z = x + 5
z = 25 + 5 = 30
The cost of one bouquet of tulips is $25, one bouquet of roses is $60, and one bouquet of lilies is $30.