Choose all the expressions that are equal to 34 × 8,010. A. 8,010 × 34
B. 34 × (801 × 102)
C. 30 × 4 × 8,010
D. 34 × (8,000 + 10)
E. (30 + 4) × 8,010

A. 8,010 × 34

D. 34 × (8,000 + 10)

E. (30 + 4) × 8,010

Step-by-step explanation:

First we need to calculate 34 × 8010 = 272340

A. 8,010 × 34 = 272340

This is equal to 34 × 8010.

B. 34 × (801 × 102)

= 34 × 81702

= 2777868

This is not equal to 34 × 8010.

C. 30 × 4 × 8,010

= 961200

This is not equal to 34 × 8010.

D. 34 × (8,000 + 10)

= 34 × 8010 = 272340

This is equal to 34 × 8010.

E. (30 + 4) × 8,010

= 34 × 8010 = 272340

This is equal to 34 × 8010.

Therefore, the correct options are:

A, D, E.

{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