SOLUTION: find equation of each line, write in slope interept and standard form (if possible). 1. through (-7,2) and perpendicular to y=2x ??? i got confused on how to find slope if i d

Question 503708: find equation of each line, write in slope interept and standard form (if possible).
1. through (-7,2) and perpendicular to y=2x ???
i got confused on how to find slope if i dont have a "b" for that y=2x equation??
AND ALSO...
2. through (-2,3) and (6,1)
AND ALSO...
3. how do you graph inequalities on a ti86 calculator? shading and all?
Answer by oberobic(2304) (Show Source): You can put this solution on YOUR website!
A line perpendicular to y = 2x will have slope = -1/2.
y = -1/2x + b
We want it to go through (-7,2), so substitute these values to find 'b'.
2 = -1/2(-7) + b
2 = 7/2 + b
b = -3/2
.
y = -1/2x -3/2
.
1/2x + y = -3/2
x + 2y = -3 in standard form
.
A line passing through (-2,3) and (6,1) can be determined.
m = change in y / change in x
change in y = 1-3 = -2
change in x = 6-(-2) = 8
m = -2/8 = -1/4
.
y = -1/4x + b
.
substitute a point you know, say (-2,3)
.
3 = -1/4*-2 + b
3 = 1/2 + b
2 1/2=b
.
y = -1/4x + 2 1/2
.
1/4x + y = 5/2
x + 4y = 10 in standard form
.
.

.
.
It is better to post new questions than to add them to an existing question. But I'll give these a try.
1. -[2x-(5x+2)] = 2+(2x+7)
HOW DO I DISTRIBUTE WITH THE NEGATIVE OUTSIDE? WHAT DO THE BRACKETS MEAN??
The square brackets are just meant to be distinctive from parentheses. In English we usually have square brackets to enclose parentheses, and curly braces to enclose square brackets. You can replace them with parentheses. But you should always work from the innermost parentheses out.
.
Let u = 5x+2 to make is simpler.
.
-(2x -u) = -2x -(-u) = -2x +u
So, replace the 'u' with what it means:
-2x + (5x+2)
.
-(2x-(5x+2)) = 2+(2x+7)
.
-2x +(5x+2) = 2 + (2x+7)
.
-2x +5x +2 = 2 + 2x + 7
.
3x + 2 = 2x + 9
.
x = 7
.
.
2. -[3X-(2X+5)] = -4 -[3(2X-4)-3X]
.
-(3x -(2x+5)) = -4 -(3(2x-4)-3x)
.
-(3x -2x -5) = -4 -(6x -12 -3x)
.
-3x +2x +5 = -4 -(3x -12)
.
-x + 5 = -4 -3x + 12
.
-x + 5 = -3x + 8
.
2x = 3
.
x = 3/2

RELATED QUESTIONS
Write in slope-intercept form (if possible) and standard form an equation of the line... (answered by mananth)

find the slope of each line. y = 2x -3 2y = -x + 4 In each pair of equations give the... (answered by ewatrrr)

Find an equation of the line,and write it in (a) slope-intercept form if possible and (b) (answered by josgarithmetic)

write an equation of each line in slope intercept form and standard form if possible.... (answered by rwm)

find the slope and y-interept if possible of the equation of the line sketch the line (answered by ReadingBoosters)

write the slope intercept form of the equation through (1, -2) and perpendicular to the... (answered by oscargut)

please help solve. find and equation of each line, and write it in slope intercept... (answered by funmath)

Directions: Find an equation of each line described. Write each equation in... (answered by josmiceli)

ok here's a few i'm not sure if they're right or not and the last one I just can't seem... (answered by stanbon)