Question

Prove that f(x) = 9x- 2 is equal to -3 when f(x) = -5.

Answer 1

To prove that f(x) = 9x - 2 is equal to -3 when f(x) = -5, we can substitute -5 for f(x) in the equation and solve for x. The value of x is -3.

Step-by-step explanation:

To prove that f(x) = 9x - 2 is equal to -3 when f(x) = -5, substitute the value of f(x) into the equation:

f(x) = 9x - 2

Now, replace f(x) with -5:

-5 = 9x - 2

Next, we add 2 to both sides of the equation:

-5 + 2 = 9x - 2 + 2

-3 = 9x

Finally, we divide both sides by 9 to solve for x:

-3/9 = 9x/9

-1/3 = x

Now we plug x back into the original equation to check if f(x) does indeed equal -3:

f(-1/3) = 9(-1/3) - 2

f(-1/3) = -3 - 2

f(-1/3) = -5

This confirms that when f(x) is -5, the function f(x) = 9x - 2 is equal to -3.

Answer 2

To prove that f(x) = 9x - 2 equals -3 when f(x) = -5, we set the function equal to -5 and solve for x, which results in x = -1/3. This might be a misunderstanding as typically we find x values for given f(x), not the reverse. If we seek the x value for f(x) = -3, through a similar process we find x = -1/9.

Step-by-step explanation:

To prove that f(x) = 9x - 2 is equal to -3 when f(x) is -5, we simply replace x in the function with the value that makes f(x) equal to -5. So, we set the function equal to -5 and solve for x:

f(x) = -5
9x - 2 = -5 | Add 2 to both sides
9x = -5 + 2
9x = -3 | Divide both sides by 9
x = -3/9
x = -1/3

Therefore, when f(x) is -5, x must be -1/3. To prove that f(x) is -3 for some value of x, we would follow a similar process, but in this case, you've provided a value for f(x), not for x, which might be a misunderstanding of the question. However, if you meant to find the value of x when f(x) is -3, the process would be:

9x - 2 = -3 | Add 2 to both sides
9x = -1 | Divide both sides by 9
x = -1/9