Question

What value of x is in the solution set of 9(2x + 1) < 9x – 18?

A: -4
B: -3
C: -2
D: -1

Answer 1

Option A is correct

-4

Explanation:

Given the equation:

`9(2x+1)<9x-18`

Using distributive property:
`a \cdot (b+c) = a\cdot b+ a\cdot c`

then;

`18x+9<9x-18`

Subtract 9x from both sides we have;

`9x+9<-18`

Subtract 9 from both sides we have;

`9x<-27`

Divide both sides by 9 we have;

`x < -3`

We can write this as:

x∈
`(-\infty, -3)`

From the given option, only x = -4 belong to the set of the solution.

Therefore, the value of x is in the solution set of 9(2x + 1) < 9x – 18 is, -4

Answer 2

For this case we have the following inequality:

`image`

Solving the inequality we have:

Distributive property:

`image`

Combine similar terms:

`18x - 9x <-9 - 18`

`image`

From here, we clear the value of x:

`image`

`image`

Therefore, the solution is given by:

(-∞, -3)

The point that belongs to the solution is:

`image`

Answer:

The value of x is in the solution set is:

A: -4