Alg 2 help

Im stupid, i forgot how to do slope >.>.

Help with my problems?

Can you explain how to do em too?


Given the following information, write equations in slope intercept form-

1. x intercept -3, y intercept of 7

^What do i do?

2. passes through (14,1) and perpendicular to the slope of -7/3.

^Again help pl0x.

3. (9,1) and (-7,3)

^last one


Ok well thats not all my problems, but if someone can explain how to do em, i can figure the rest out. Help me please.

 

In case you've forgotten, slope-intercept form is
y = mx + b
Where m is the slope of the line (rise/run) and b is the y-intercept.
Also, the formula to find the slope is
(y2-y1)/(x2-x1)
Where (x1, y1) is a point on the line, as is (x2, y2)

1. The X intercept is where y = 0 and vice versa with the Y intercept, so the following are two points on the line.
(-3, 0)
(0, 7)
Simply plug these values into the slope formula and simplify
m = (y2-y1)/(x2-x1)
m = (-3-0)/(0-7)
m = -3/-7
m = 3/7
y = mx + b
y = 3/7x + 7

2. If a line is perpendicular to another line, its slope is the opposite reciprocal
m = 3/7
y = 3/7x + b
Then plug in the values for x and y in the given point, and solve for b
1 = (3/7)*14 + b
1 = 6 + b
b = -5
y = 3/7x - 5

3. Plug them into the slope formula to find the slope
m = (3-1)/(-1-9)
m = 2/-10
m = -1/5
y = -1/5x + b
Then do what we did in the above problem, and substitute either point's values for x and y
1 = (-1/5)*9 + b
1 = -9/5 + b
-14/5 = b
y = -1/5x - 14/5

 

Yeah....Jimmy is a genius. I could've done it though, too lazy

 

Thanks bro )