Answer:
3/5
Step-by-step explanation:
There are 20 balls, numbered 1 through 20.
Of these, 10 are even, 4 are less than five, and 2 are both even and less than 5.
So the probability is:
P(even or <5) = P(even) + P(<5) − P(even and <5)
P(even or <5) = 10/20 + 4/20 − 2/20
P(even or <5) = 12/20
P(even or <5) = 3/5
Answer:
Because the kind of compounfds that you try to determine using paper chromatography (organic compounds) are usually not soluble in water. Furthermore, water could react chemically with some of this compounds, because it's a very reactive molecule. You need organic solvents that are mostly inert.
Solve by Substitution
Answer:
x = -5
y = -2
Sorry it's wrong the correct answer is 5.
3 5
-- ÷ ----
1 3
cross out the 3's
5
-- ÷ ----
1
In order to add or subtract fractions,they must have the same denominator.
Change one of these fractions to have the same denominator as the other one,
and you'll be able to add them.