Keith went to the mall on saturday to buy clothes. he paid $13.05 on a shirt and $9.40 on a jacket with two $20 bills. how much money did keith get in change?

The answer is $17.55.

Explanation:

All you have to do to find the answer is add $13.05 and $9.40 to get $22.45. Then, it says he paid with two $20 bills, which is $40. So after that, all you do is subtract $40-$22.45.

Hope this helps :)

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.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15