I think the answer might be 72
Answer:
a
Step-by-step explanation:
if you plug 4 in for x it solves it
Answer:
D. About 800 years
Step-by-step explanation:
Use the half-life equation:
A = A₀ (½)ⁿ
where A is the final amount,
A₀ is the initial amount,
and n is the number of half-lives.
0.90A₀ = A₀ (½)ⁿ
0.90 = (½)ⁿ
To solve for n, take log of both sides:
log 0.9 = n log 0.5
n = (log 0.9) / (log 0.5)
n = 0.152
It takes 0.152 half-lives. The half-life of carbon-14 is 5730 years.
0.152 × 5730 years = 871 years
The closest answer is D.
2.
We have a transversal across parallel lines so we get the usual array of congruent and supplementary angles. We just have to figure out which is which, and the diagram, even though not to scale, makes it pretty obvious.
Angle x isn't the same as the 40° angle so it must be its supplement.
Answer: C 140°
3.
r=1.2, h=2.9, V = (1/3) πr²h
Nothing hard here, we just plug in the numbers,
V = (1/3) π (1.2)² (2.9) ≈ 4.37310
Answer: B. 4.4 cubic inches
4.
Dilation by .5 makes a similar triangle, and reflection is an isomorphism (i.e. it doesn't change the size or shape) so the answer is
Answer: B similar not congruent
5.
The corresponding interior and exterior angles of a triangle form a linear pair, so supplementary angles. x=180-110 = 70°
Answer: A 70°
Answer:
-115/69
Step-by-step explanation:
12(6x + 10) + x = 9x + 5(1 - x)
72x + 120 + x = 9x + 5 - 5x
73x + 120 = 4x + 5
69x = 5 - 120
69x = -115
x = -115/69
