To buy a computer, Raquel borrowed $3,000 at 9% simple interest for 4 years. How much money did she

have to pay back? (Hint: Combine both the principal and

simple interest for money she has to pay back).

$4080

Step-by-step explanation:

We have the amount she will pay back, but first, we need to find the Interest accrued.

Simple Interest is given as:

where P = principal

R = rate

T = time taken (in years)

Therefore, the interest on $3,000 at 9%  simple interest for 4 years is:

I = $1080

Therefore, the amount she will pay back is:

$3000 + $1080 = $4080

3, 12, 48, 384, 1536, 6144, 24576, 98304

step-by-step explanation:

just keep timing it by 4.

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1