Solve for x: −2x + 5 < 7

A. x > −1
B. x < −1
C. x > −6
D. x < −6

A

Step-by-step explanation:

To solve for x, we need to get x by itself

−2x + 5 < 7

First, move all the numbers to the same side of the inequality. To do this, subtract 5 from both sides.

-2x +5-5 <  7-5

-2x < 2

Now, all the numbers are on the same side. x is still not by itself, though, it is being multiplied by -2. To undo this, divide both sides by -2

-2x/2 < 2/-2

Since we divided by a negative number, we must flip the inequality sign

x > -1

Therefore, choice A is correct

answer: t=3

step-by-step explanation:

{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