Answer:
(0,20)
Step-by-step explanation:
1) we can represent the situation as coordinates
lets have # of texts be "x" variable
lets have bill be "y" as the y variable is always the dependant variable and the cost of the phone bill is dependant upon the number of texts so
y=mx+b-slope-intercept form
coordinates: (50,25) and (100,30)
slope: (30-25)/(100-50)
5/50=1/10
hence slope=1/10
y=1/10x+b
substitute in a coordinate pair into this equation
25=50*1/10+b
25=5+b
b=20
hence y intercept is (0,20)
55% of 1800 = 0.55(1800) = 990...so there are 990 girls in the school
30% of 990 = 0.30(990) = 297...so there are 297 girls who take the bus
so our slope is undefined, that means a vertical line, check the picture below
(x + 2)(x - 5)(x - 8)
Substitute them into each other to get the whole equation)
