You can use the discriminant rule, which is :
b^2 -4ac
“exactly one solution” means that it is equal to zero
so:
b^2 -4(4)(9)=0
b^2 -4(36)=0
b^2 -144=0
b^2=144
square root both sides
b=12 or -12
hope this helps !
(1) 20:4=5:1. 80:16 16 weeks since he’s doing 5per week, and 80 divided by 5 is 16.
(2) 6:3=2:1. 10:5 It will take 5 hours because she’s walking 2km per hour, so it would take 5 hours to walk 10km.
(3) 1:20 4:80 It will take 80 minutes because 20x4=80
(4) 1:1 20:20 it will take her 20 days since she makes one craft a day and she’s making 20.
(5) 12:1 84:7 84 cakes since there is 7 days in a week. 12x7=84
If you still need help, here’s the answers
Answer:
Y=3/5x -4/5
Step-by-step explanation:
3/5 is the slope so you do 3/5x
-4/5 is negative because the line passes two negative coordinates
Hope this helps!