8 .. 4 x 4 x 1/2 = 8 ... sorry if I’m wrong
Answer:
A) 277 million years
Step-by-step explanation:
Here, decay of U-238 is first order reaction. (since most of the nuclear decays are first order).
so, the equation t =
× ln(
)
where, t = time from start of reaction
k = reaction constant
A(0) = initial concentration; A = present concentration.
⇒ 4.5 billion = 4500 million years =
× ln2.
Now, given 95.82% of parent U-238 isotope is left.
⇒ t =
× ln(
)
t =
× ln(
)
⇒ t ≅ 277 million years.
Suppose that Eldi has x years old now :
x + 4 = 3 × ( x - 10 )
x + 4 = 3x - 30
Add both sides 30
x + 4 + 30 = 3x - 30 + 30
x + 34 = 3x
Subtract both sides x
x - x + 34 = 3x - x
34 = 2x
2x = 34
Divide both sides by 2
2x ÷ 2 =34 ÷ 2
x = 17
_____________________________
Thus Eldi is 17 .
2(exponent2)n(exponent11)p(exponent6)
Answer:A girrafe runs at a rate of 32 miles per hour. Which equation models the situation?
Step-by-step explanation: