..Answer:
Step-by-step explanation:
...
Answer:
D)35
Step-by-step explanation:
14%4=3.5
3.5×10=35
to be sure that 2 of them will be blue i have to select 7+2=9 balls
7+8=15 balls in the urn
P=9/15
to be sure that 4 of them will be yellow i have to select 8+4=12 balls
P=12/15
Get it to equal 0
minus 17x from both sides
2x²-17x+35=0
tricky part
get something like
(2x-a)(x-b)
we know the signs are negative since the middle term is negative and last term is positive
so a and b are either 1 and 35 or 5 and 7
(2x-1)(x-35), nope
(2x-35)(x-1) nope
(2x-5)(x-7), nope
(2x-7)(x-5), yep
(2x-7)(x-5)=0
set to zero
2x-7=0
2x=7
x=7/2
x-5=0
x=5
x=7/2 and 5
