a. use the month for x
Income
point (1,1500) (2 3500)
slope (y2-y1)/(x2-x1) =(3500-1500)/(2-1)=2000
y-y1=m(x-x1)
y-1500 = 2000(x-1)
y-1500=2000x-2000
y = 2000x-500
Expenses
point (1,21400) (2 18800)
slope (y2-y1)/(x2-x1) =(18800-21400)/(2-1)=-2600
y-y1=m(x-x1)
y-21400 = -2600(x-1)
y-21400=-2600x+2600
y = -2600x+24000
b 2000x-500=-2600x+24000
add 2600x to each side
4600x -500 = 24000
add 500 to each side
4600x = 24500
divide by 4600
x=5.326 months
Solve the system by graphing
{2x - 4y = -4 -4y = -2x-4 y = 1/2x +1 slope is 1/2 y intercept 1
{3x - y = 4 -y =-3x +4 y = 3x-4 slope is 3 y intercept is -4
this one you have to do cannot graph here the solution is x=2, y=2
Classify the system without graphing
{y = 12 - 5x
{x - 4y = -6
independent system
dependent system is the same line and has infinite solutions
inconsistent system has no solutions (parallel lines)
