A group of friends ordered 3 burgers and 3 medium fries for a total of $17.55. The price of a burger is .75 more than two times the price of medium fries. What is the cost of one burger?

Cost price of the burger = $4.15

Step-by-step explanation:

Given data:

3 burgers were ordered

3 medium fries were ordered

Total order cost 17.55

Let the price of the burger be X

Let the price of the medium fries be Y

Equation for the total sale will be 3X + 3Y = 17.55 (equation 1)

from this statement 'The price of a burger is .75 more than two times the price of medium fries.'

X - 2Y = 0.75 (equation 2)

There are now two equations and two unknowns, a simultaneous equation is solved to find the cost of the  burger.

Many methods can be used to solve these equations but in this case substitution will be used

From equation 2

X = 0.75 + 2Y (equation 3)

Substituting equation 3 into equation 1

3(0.75 + 2Y) + 3Y = 17.55

2.25 + 6Y + 3Y = 17.55

6Y + 3Y = 17.55-2.25

9Y = 15.3

Y = 1.7

Substituting Y into equation 3

X = 0.75 + 2Y

X = 0.75 + 2(1.7)

X = 0.75 + 3.4

X = 4.15

Therefore the cost price of the burger is $4.15

simplifying

5(x + -6) = 2(x + 3)

reorder the terms:

5(-6 + x) = 2(x + 3)

(-6 * 5 + x * 5) = 2(x + 3)

(-30 + 5x) = 2(x + 3)

reorder the terms:

-30 + 5x = 2(3 + x)

-30 + 5x = (3 * 2 + x * 2)

-30 + 5x = (6 + 2x)

solving

-30 + 5x = 6 + 2x

solving for variable 'x'.

move all terms containing x to the left, all other terms to the right.

add '-2x' to each side of the equation.

-30 + 5x + -2x = 6 + 2x + -2x

combine like terms: 5x + -2x = 3x

-30 + 3x = 6 + 2x + -2x

combine like terms: 2x + -2x = 0

-30 + 3x = 6 + 0

-30 + 3x = 6

add '30' to each side of the equation.

-30 + 30 + 3x = 6 + 30

combine like terms: -30 + 30 = 0

0 + 3x = 6 + 30

3x = 6 + 30

combine like terms: 6 + 30 = 36

3x = 36

divide each side by '3'.

x = 12

simplifying

x = 12

this should .

the answer is b.

64

step-by-step explanation:

c=2πr=2·π·8≈64