234.A 124/B 136.B 156.D

If 8 g of a radioactive substance are present initially and 2 yr later only 4 g remain, how much of the substance will be presen

My name is Ann [436]

Answer:

none

Step-by-step explanation:

8-4=4

if every 2 years, 4 gallons disappear

then every 1 year, 2 gallons disappear

meaning that by 5 years there will be no substance left.

(5*2=10)

7 0

3 years ago

B) Solve x + 5x – 14 = 0

Nastasia [14]

5x+x=14
14/6= 2.3
x=2.3

4 0

4 years ago

Read 2 more answers

NEED HELP WITH THESE QUESTIONS

amm1812

For this case we must solve the following questions:

Question 1:

We should simplify the following expression:

$\frac {\frac {m ^ 2 * n ^ 3} {p ^ 3}} {\frac {mp} {n ^ 2}} =$

Applying double C we have:

$\frac {m ^ 2 * n ^ 3 * n ^ 2} {mp * p ^ 3} =$

By definition of multiplication of powers of the same base we have to place the same base and add the exponents: $\frac {m ^ 2 * n ^ 5} {m * p ^ 4} =$

Canceling common terms:

$\frac {mn ^ 5} {p ^ 4}$

Answer:

Option A

Question 2:

We should simplify the following expression:

$\frac {3xyz ^ 2} {6y ^ 4} * \frac {2y} {xz ^ 4}$

So, we have:

$\frac {3xyz ^ 2 * 2y} {6y ^ 4 * xz ^ 4} =\\\frac {6xy ^ 2z ^ 2} {6y ^ 4xz ^ 4} =$

Simplifying common terms:

$\frac {1} {y ^ 2z ^ 2}$

Answer:

Option D

Question 3:

We factor the following expressions to rewrite the experience:

$r ^ 2 + 7r + 10$ : We look for two numbers that multiplied give 10 and added 7:

$(r + 5) (r + 2)$

$r ^ 2-5r-50:$ We look for two numbers that multiplied give -50 and added -5:

$(r-10) (r + 5)$

$3r-30 = 3 (r-10)$

Rewriting the given expression we have:

$\frac {(r + 5) (r + 2) * 3 (r-10)} {3 (r-10) (r + 5)} =$

We simplify common terms in the numerator and denominator we have:

$(r + 2)$

Answer:

Option D

4 0

3 years ago

Read 2 more answers

The local humane society currently has 60 cats if 300 animals are in the shelter what percent are the cats

Kaylis [27]

20% are cats.

20 cats/300 total animals=0.2

0.2 is the same thing as 20%.

7 0

3 years ago

H is between points Q and R. QH=23 and HR=12. What is the length of QR

PSYCHO15rus [73]

Answer:

35

Step-by-step explanation:

Given:

GH = 23

HR = 12

Required:

Length big QR

SOLUTION:

Since H is a point in between points Q and R, points Q, H, R are collinear.

QH = 23

HR = 12

QH + HR = QR (segment addition postulate)

23 + 12 = QR (substitution)

35 = QR

Therefore, the length of QR is 35

3 0

4 years ago