120, 90, 30 if you're going from the depths of the water to water level
The distance formula is an algebraic expression used to determine the distance between two points with the coordinates (x1, y1) and (x2, y2).
<span><span>D=<span><span>(<span>x2</span>−<span>x1</span><span>)2</span>+(<span>y2</span>−<span>y1</span><span>)2</span></span><span>−−−−−−−−−−−−−−−−−−</span>√</span></span><span>D=<span>(<span>x2</span>−<span>x1</span><span>)2</span>+(<span>y2</span>−<span>y1</span><span>)2</span></span></span></span>
Example
Find the distance between (-1, 1) and (3, 4).
This problem is solved simply by plugging our x- and y-values into the distance formula:
<span><span>D=<span><span>(3−(−1)<span>)2</span>+(4−1<span>)2</span></span><span>−−−−−−−−−−−−−−−−−−</span>√</span>=</span><span>D=<span>(3−(−1)<span>)2</span>+(4−1<span>)2</span></span>=</span></span>
<span><span>=<span><span>16+9</span><span>−−−−−</span>√</span>=<span>25<span>−−</span>√</span>=5</span><span>=<span>16+9</span>=25=5</span></span>
Sometimes you need to find the point that is exactly between two other points. This middle point is called the "midpoint". By definition, a midpoint of a line segment is the point on that line segment that divides the segment in two congruent segments.
If the end points of a line segment is (x1, y1) and (x2, y2) then the midpoint of the line segment has the coordinates:
<span><span>(<span><span><span>x1</span>+<span>x2</span></span>2</span>,<span><span><span>y1</span>+<span>y2</span></span>2</span>)</span><span><span>(<span><span><span>x1</span>+<span>x2</span></span>2</span>,<span><span><span>y1</span>+<span>y2</span></span>2</span>)</span><span>
</span></span></span>
To solve this question, we just need to insert 12 into the m position of each question and see if the equation holds true.
a. 4m = 40
4(12) = 40
48 = 40
48 obviously does not equal 40, so it is not choice A.
b. m + 20 = 42
12 + 20 = 42
32 = 42
Again, 32 isn't the same as 42, so not choice B either.
c. 4m = 48
4(12) = 48
48 = 48
It looks like this one is true, but let's solve D also just to make sure.
d. m - 4 = 9
12 - 4 = 9
8 = 9
This is false, since 8 does not equal 9.
Therefore, choice C (4m = 48) is the correct answer.
Hope that helped! =)
Answer:
Q2: slope = -½
Q3: slope = 1
Step-by-step explanation:
If the equation of the line is in the form y = mx+b, then m is the slope of the line and b is the y-intercept (the point where the line crosses the x-axis).
y = -½x, so the slope of the line is -½
y = x+15, so the slope of the line is 1
