Formulas
What is the Slope Formula
y2-y1/x1-x2
Slope= 3/2 Y-intercept = -7
y=3/2x-7
y=7x+2 and y=7x-1
Parallel
(-4,-1); y=2x+4 (parallel)
y=2x+7
y=mx+b
6x+8y=-32
y=-3/4x-4
y=-1/3x+2 and y=1/3x
Neither
(3,-3); y=3/4x+5 (perpendicular)
y=-4/3x+1
While visiting crimson lake, Sally decided to go kayaking. The rangers charge $8.50 per hour in addition to a $25.00 deposit to rent the kayak. If she rented the kayak from 11:30 a.m. to 2:30 p.m., write and solve a linear equation to find the total cost to rent the kayak.
m=8.50 y=8.50x+25.00
B=25.00 y=8.50(3) +25
y=$50.50
What is standard form
Ax+By=C
8x-4y=16
y=1/2x-4
line AB formed by (3,1) and (3,-4)
Line CD formed by (-4,1) and (-4,5)
Line AB: M= undef
Line CD: M= Undef
Parallel
(-6,7); 5x+2y=10 Parallel
y=-5/2x-8
Tickets at a school play cost $4 in advance or $5 at the door. Total ticket sales for an evening production were $440. If no tickets were sold in advance, write and solve a linear equations to find the how many were sold at the door.
x= advance 4x+5y=440
y= door 4(0)+5y=440
y=88 tickets
What is point slope formula
y-y1=m(x-x1)
(6,-1); slope= -1/3
y=-1/3x+1
Line AB formed by (-3,8) and (3,2)
Line CD formed by (7,1) and (5,-1)
Line AB: M=-1
Line CD: M= 1
Perpendicular
(-1,6); x+3y=6
y=3x-3
A home security company provides security systems for $5 per week, plus an installation fee. The total fee for 12 weeks of service is $210. Write and solve a linear equation to the cost of the installation fee.
M= 5 ; (12,210)
y-210=5(x-12)
y=150
(2,-1) and (4,-6)
y=-5/2x+4
3x-y=2 and 12x-4y=4
y=3x-2 and y=3x-1
M=3 and M=3
Parallel
To surf the internet for 15 minutes at an airport, it cost $4.05. For 40 minutes, it cost $5.80. Write and solve a linear equation to find the cost for surfing the web for one hour.
(15, 4.05); (40, 5.80)
5.80-4.05/40-15= 1.75/25=.07
y-4.05=.07(x-15)
y=.07x+3 y=.07(60)+3 y=$7.20