Two cars are traveling down the highway at the same speed. if the first car traveled at a speed 10 kilometers per hour more than now, and the other car traveled at a speed 10 kilometers per hour less than now, then the first car would cover the same distance in two hours as the second car in three hours. what is the speed of the cars?

  50 km/h

Step-by-step explanation:

Before the speed adjustments, their speeds were in the ratio 3:2. The difference in their speeds was 10 + 10 = 20 km/h, corresponding to a difference of 3-2 = 1 ratio unit.

Hence the faster car was traveling at 3×(20 km/h) = 60 km/h, and the slower car was traveling at 2×(20 km/h) = 40 km/h. After the speed adjustments, both cars are traveling at 50 km/h.

{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

answer:   c ?

step-by-step explanation: