Problem Help Flag 2 M 15 is the midpoint of RS IfS has coord
Solution
2) Given Points R ans S.
R=(7,-3) Let s be (x,y)
Mid point of RS is M(-1,-5)
mid point is the average of two points.
So, (7+x)/2 = -1 and (-3+y)/2 = -5
7+x=-2 -3+y=-10
x=-2-7 y=-10+3
x=-9 y=-7
Therefore, S is (-9,-7)
So, option B is correct.
3) Given equation of line is -3x-5y=-10 and a point (2,-1)
equation of line is -3x-5y=-10
It can be taken in slope intercept form.
-3x-5y=-10
5y=-3x+10
y=(-3/5)x+(10/5)
y=(-3/5)x+2
So, slope is -3/5,
The line perpendicular to this -3x-5y=-10 line has slope of 5/3.
General slope intercept form can be taken as y=mx+c
y=(5/3)x+c
3y=5x+3c
This line passes through the point (2,-1)
3y=5x+3c
substitute (2,-1) in the above to get c
3(-1) = 5(2)+3c
-3 = 10+3c
3c=-3-10
3c=-13
The equation of a line is 3y=5x+3c
3y=5x+(-13)
3y=5x-13
5x-3y=13
Therefore the equation of a line perpendicular to -3x-5y=-10 and passing through (2,-1) is 5x-3y=13
So, option A is correct.
4) Given equation is y=3x+4 and a point (5,-2)
Need to find the line parallel to y=3x+4 and passing through the (5,-2)
Slope of y=3x+4 is \'3\' because it is in Slope intercept form y=mx+c where m-slope
The required line has the slope \'3\' because required line is parallel to given line.
So, required line is y=3x+c
This line passes through the point (5,-2)
y=3x+c
-2=3(5)+c
-2=15+c
c=-2-15
c=-17
The required line is y=3x+c
y=3x-17
Therefore, Option B is correct.


