1) 8 x 5 + 4 - 3 x 8
=20
2) 7 x 7 - 3 x 4 + 8 - 4
=41
3) 6 x 5 + 7
=37
4) 6 x 3 - 10/5
=16
5) 7 + 3(9 x 6 - 5 x 5)
=87x + 7
Hopefully that’s right :)
Do 2/5+5/7 and there's your answer. 2/5+5/7=14/35+25/35=39/35=1 4/35. :)
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.
Are you given choices?
Plug in the x- and y-coordinates of the given points.
The ones that make the inequality true are solutions.
Convert 30% to a decimal by dividing by 100 = 0.30
Multiply by the cost of the helmet, $50
50 x 0.30 = $15, the amount of the discount.
50-15 = $35, the sale price of the helmet.
For the sales tax, again, convert to a decimal by dividing by 100 = 0.06
35 x 0.06 = 2.10, the amount of sales tax
$35 + $2.10 = $37.10, total cost with tax