Lawrence bought 2/3 pound of roast beef. He used 3/4 of it to make a sandwich. How much beef did he use for his sandwich A 5/12 pound B 1/2 pound C 5/7 pound D 6/7 pound

B) 1/2 pound

Step-by-step explanation:

Lawrence bought 2/3 pound of roast beef.

He used 3/4 of it to make a sandwich.

The amount of beef that he used for his sandwich is calculated as:

3/4 of 2/3 pounds of roast beef

3/4 × 2/3

= 6/12 pound

= 1/2 pound

Option B is the correct Option.

{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