Evaluate. 2.2^3 . 2^-5 .2^-1

A. -4
B, -8
C. 1/4
D. 1/8

Step-by-step explanation:

2^3 . 2^- 5 . 2^- 1

= 2^( 3 - 5 - 1 )

= 2^( 3 - 6 )

= 2^- 3

= 1 / 2^3

= 1 / 8

If

2 . 2^3 . 2^- 5 . 2^- 1

= 2^1 . 2^3 . 2^- 5 . 2^- 1

= 2^( 3 - 5 - 1 + 1 )

= 2^( 3 - 5 )

= 2^- 2

= 1 / 2^2

= 1 / 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

(1 km=1000m, 1m=100 cm)