Well, if you know how to find x, it's really just a matter of distributing, and then finding the value of x.
8 is outside the parentheses, and 2x and 9 are inside the parenthesis, telling us that 8 needs to be distributed to the numbers inside the parentheses. Once distributed to both numbers inside the parentheses, you would end up with : 16x + 72 = 56.
Now, there's just the matter of finding the value of x. Let's start with the numbers without any variables with them, and the side that doesn't have the answer. 72. Subtract 72 from both sides, and you're left with : 16x = -16.
We have to isolate the variable, and therefore, we would have to get rid of that 16 with it. So we divide both sides by 16. x ends up by itself, and -16 ÷ 16 is -1.
X=-1 First, divide both sides by 8 to eliminate 8 on the left side. You should result in 2x+9=7 Second, subtract 9 from both sides, which results in 2x=-2 Third, Divide both sides by 2 and you get x=-1
There is a horizontal line test but the question asks to use the vertical line test. Using the horizontal line test you would get that the function is not one to one but using the vertical line test you would get its one to one.
