Slope-Intercept Form
Write the equation of each line in slope – intercept form.
m=-3, b=7
y=-3x+7
Write an equation in point-slope form.
(-3,4); m=-5
y-4=-5(x+3)
Suppose y varies directly as x. If x = 9 and y = 54, Find x if y = 72.
x=12
Write an equation of the line in slope-intercept form that is parallel to the given line.
(6,4); y=1/3x+1
y=1/3x+2
Write the equation of each line in slope – intercept form.
slope=1/2, y-intercept=-3
y=1/2x-3
Write an equation in point-slope form.
(4,-2) (8,1)
y+2=3/4(x-4)
y-1=3/4(x-8)
Suppose y varies directly as x and y = -24 when x = 4. Find y when x = 32.
y=-192
Write an equation in slope-intercept form that is parallel to the given.
(-4,2); y=x+9
y=x+6
Write the equation of each line in slope – intercept form.
(0,7); m=2
y=2x+7
Write an equation in point-slope form.
(7, -6), (-1, -6)
y+6=0(x-7)
y+6=0(x+1)
**y=-6
Barbara is starting a smart phone repair business. She charges a flat fee of $75 and an additional $10.50 per hour. Write an equation that models the total amount earned, y (in dollars) in terms of x, the number of hours.
y=10.50x+75
The distance a vehicle travels varies directly with time. If a vehicle can travel 200 miles in 3 hours, how long would it take the same vehicle to travel 550 miles?
About 8.5 hours
Write an equation in slope-intercept form that is perpendicular to the given.
(-5,-1); y=5/2x-3
y=-2/5x-3
Write the equation of each line in slope – intercept form.
(0,-3) (1,1)
y=4x-3
Write an equation in point slope form.
m=2; (-1,-4)
y+4=2(x+1)
Rachael is getting her car repaired and the auto shop charges a flat fee of $70 along with $12 per hour for the labor. Writing an equation that shows how much Rachael will be spending on her car.
y=12x+70
The weight an object exerts on a scale varies directly with the mass of an object. If a bowling ball has a mass of 6 kg, the scale reads 54. If another object has a mass of 8 kg, what would the scale read?
Scale: 72
Write an equation in slope-intercept form that is perpendicular to the given line.
(-8,3); y=4x-7
y=-1/4x+1