Question

How the bloody hell do I answer these? Please explain how you did it.

1. In the xy plane, line m passes through the points (a,0) and (0,2a), where a>1. What is the slope of line m?
a)-2 b)-1/2 c)2 d)-2a e)2a

2. First, 3 is subtracted from x and the square root of the difference is taken. Then, 5 is added to the result, giving a final result of 9. What is the value of x?
a)3 b)4 c)5 d)16 e)19

3. If S is the set of positive that are multiples of 7, and if T is the set of positive integers that are multiples of 13, how many integers are in the intersection of S and T?
a)none b)one c)seven d)thirteen e)more than thirteen

4. A florist buys roses at $0.50 each and sells them for $1.00 each. If there are no other expenses, how many roses must be sold in order to make a profit of $3.00?
a)100 b)150 c)200 d)300 e)600

Answer 1

1. the formula for the slope is

`(y2 - y1)/(x2 - x1)`
where (a,0) is x1, y1 and (0,2a) is x2, y2. try to see if you can do it now (:

2. take a number x, then step by step do whatever the question asks for example "First, 3 is subtracted from x" so you know the first thing you need to do is x-3, then go on and you'll get an equation which you can use to solve for x, try it!

3. make a set, S, which has multiples of 7. then make a set, T, which has multiples of 13.
now the intersection of S and T is a set having all elements of S, also found in T (basically the numbers that are common to both). try doing it now!

for fourth, this requires a profit formula(that I do not know), must be explained in your book, try going over it, I'm sure you'll find it there!