Sun lei bought a laptop computer for $1800.
the total cost, including tax, came to $1890.
what is the tax rate?

Subtract to find the amount of tax paid:

1890 - 1800 = 90

Divide the amount of tax by the price of the computer:

90 / 1800 = 0.05

Multiply the decimal by 100:

0.05 x 100 = 5%

The tax rate is 5%

a. she will receive a refund of $278.

step-by-step explanation:

set each factor equal to 0

4x-3 = 0

2x-1 = 0

solve for x.

4x-3=0

4x=3

x= 3/4

solve for x. 

2x-1= 0

2x= 1

x= 1/2

eventually after a few more steps, your answer should be 1/2 is less than or equal to x and 3/4 is greater than or equal to x