Answer:
Step-by-step explanation:
3x - 1 = 3x + 7
-1 ≠ 7
no solution
We know that she spent $39, and has 3/4 of the original amount left. Our goal is to find the original amount. We can use the equation. x - 39 = 3/4x. Once we subtract x on the left hand side, we get -39 = -1/4x. Once we multiply -39 by -4, we get 146. She originally had $156.
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.
-50 to -51; 49 to 50; -48 to -49; 48 to 49; 50 to 51
I just add one
Answer:
Step-by-step explanation:
The scenario is illustrated in the attached photo.
Desiree drove north for 30 minutes at 50 miles per hour.
Distance = speed × time
Distance travelled by Desiree to the north is 50 × 30 = 1500 miles
Distance travelled by Desiree back from the north and to the south is
60 × 20 = 1500 miles
She started from south and drove 1500 miles towards the north. She returned by driving 1200 miles again towards south . Distance of Desiree from where she started will be 1500 - 1200 = 300 miles.
She is 300 miles from her starting position and she is in the southern direction.