Plsara is selling cookies and brownies as a fundraiser for the school band. she charges $2.25 for two cookies and one brownie. she charges $5.75 for four cookies and three brownies. how much does sara charge per cookie? how much per brownie? a. $0.50 per cookie, $1.25 per brownie b. $0.75 per cookie, $1.50 per brownie c. $0.25 per cookie, $1.00 per brownie d. $1.00 per cookie, $1.00 per brownie

The cost of the  $0.5 per cookies and $1.25 per brownie.

Option (A) is correct.

Step-by-step explanation:

Let us assume that the cost of the cookies =x

Let us assume that the cost of the brownie = y

As given

Sara is selling cookies and brownies as a fundraiser for the school band.

She charges $2.25 for two cookies and one brownie.

Than the equation becomes

2x + y = 2.25

She charges $5.75 for four cookies and three brownies.

4x + 3y = 5.75

Than two equation are

2x + y = 2.25  and 4x + 3y = 5.75

Multiply 2x + y = 2.25  by 3 and subtracted from 4x + 3y = 5.75

4x - 6x + 3y - 3y = 5.75 - 6.75

-2x = - 1

2x = 1

x = $0.5

Put in the equation 2x + y = 2.25

2 × 0.5 + y = 2.25

1 + y = 2.25

y = 2.25 - 1

y = $1.25

Therefore the cost of the  $0.5 per cookies and $1.25 per brownie.

Option (A) is correct.

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.