Nicole bought a desktop computer and a laptop computer. Before finance charges, the laptop cost $ 300 more than the desktop. She paid for the computers using two different financing plans. For the desktop, the interest rate was 6 % per year, and for the laptop it was 7 % per year. The total finance charges for one year were $ 398 . How much did each computer cost before the finance charges?

Step-by-step explanation:

The given conditions allow us to write two equations. Let d and L represent the costs of the desktop and Laptop computers, respectively. Then we have ...

  L -d = 300

  .07L +.06d = 398

Multiplying the first equation by 0.06 and adding that to the second equation, we have ...

  .06(L -d) +(.07L +.06d) = .06(300) +(398)

  0.13L = 416

  L = 416/.13 = 3200

  d = 3200 -300 = 2900

The desktop computer cost $2900; the laptop computer cost $3200.

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116