Selena purchased some gifts for her nieces and nephews online. She bought 3 dolls each priced at $19.99 each and 4 remote control cars priced at $21.99 each. Selena was able to get an online coupon for $3 off on each remote
control car that she purchased. There was no sales tax, but the shipping charge was $10.50. What was the total
amount Selena paid for her online purchase?
a $135.93
b. $144.93
$146.43
d $155.43

C . $146.43

Step-by-step explanation:

lets use variables

dolls = d

remote cars = r

3 * 19.99 = $59.97

4 * 21.99 = $ 87.96

since there was a discount for each car bought, deduct from total cost

$87.96 - 4*3 = $75.96

now add the cost of the dolls and cars as well as the shipping cost :

59.97 + 75.96 + 10.5

= $ 146.43

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)