Ac method
for y=ax^2+bx+c
the ac method is normally used for when a≠1
it is used as an aid to help factor
so
0=1x^2-8x+15
multiply a and c (1 times 15=15)
what 2 numbers mulitply to get 15 and add to get -8?
-3 and -5
split the middle up to that
0=1x^2-3x-5x+15
group
0=(x^2-3x)+(-5x+15)
undistribute
0=x(x-3)-5(x-3)
undistribute (x-3)
0=(x-5)(x-3)
set to zero
x-5=0
x=5
x-3=0
x=3
solutions are x= 3 and 5
Answer:
13<x<39 (range of hours)
Step-by-step explanation:
2<x<6 (x is the range of days)
Since each workday is 6.5 hours, multiply everything by 6.5:
13<x<39 (the new x is the range of hours)
Answer:
Step-by-step explanation:
Total cost (both cars) 3 * 104 dollars
