Answer:
2 and 9 are correct. The remainder need to be reconsidered.
Step-by-step explanation:
Your answer to 9 is correct, which means you have the appropriate signs for the point coordinates. In your other point-slope questions, one or more of the signs is incorrect. Use your good work as an example of how to choose the correct answers elsewhere.
1) When you have y = kx, you can find the value of k from ...
... k = y/x
When the variation is direct, this works for any (x, y) pair.
3) A unit rate is called a unit rate because it has 1 (a unit) in the denominator.
4a, 4b, ... all slope calculations. You managed to get it right in problem 9. Watch your signs.
10, 11 ... It can work well to put the x term on the same side with the y-term, then multiply the equation by the denominator value.
... (2/3)x + y = 7 . . . . add (2/3)x to both sides of the equation
... 2x + 3y = 21 . . . . . multiply by 3. (Standard form <em>always</em> has the leading coefficient positive.)
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Whenever you consider making a term disappear from one side of the equation, think in terms of adding its opposite to both sides of the equation. This will give the result you want and is consistent with the properties of equality: <em>whatever you do to one side of the equation you must also do to the other side of the equation</em>. Other wording may have been used by your teacher or friends. This is <em>the one true statement about transforming equations</em>.
