# Test 1 sec 4 #27 please!

Test 1 sec 4 #27 please!

# Can you explain this algebraically (even if you also give a graphed explanation)?

Can you explain this algebraically (even if you also give a graphed explanation)?

Radioactive substances decay over time. the mass M, in grams, of a particular radioactive substance d days after the beginning of an experiment is shown in the table below:

Number of days, d Mas, M (grams)
0 120.00
30 103.21
60 88.78
90 76.36

If this relationship is modeled by the function M(d) = a • 10^bd, which of the following could be the values of a and b?

A) a = 12 and b = 0.0145

B) a = 12 and b = -0.0145

C) a = 120 and b = 0.0022

D) a = 120 and b = -0.0022

# College Board Test 4, Math 4 #25 (the explanation link that you previously made does not work)

College Board Test 4, Math 4 #25 (the explanation link that you previously made does not work):

f(x) = 2x^3 + 6 x^2 + 4x
g(x) = x^2 + 3x + 2

The polynomials f(x) and g(x) are defined above. Which of the following polynomials is divisible by 2x + 3?

A) h(x) = f(x) + g(x)

B) p(x) = f(x) + 3 g(x)

C) r(x) = 2 f(x) + 3 g(x)

D) s(x) = 3 f(x) + 2 g(x)

# In your PWN Math Book Fourth Edition on page 87 question 5…

Hi Mile,
In your PWN Math Book Fourth Edition on page 87 question 5, I do not understand why 6.5 changed to negative 6.5 when you took the absolute value of both sides. Wouldn’t it stay 6.5?
Thank you

# Hi! Can you please explain number 1 on page 242 on the 4th edition of the PWN book?

Hi! Can you please explain number 1 on page 242 on the 4th edition of the PWN book?

# Which could be the x-coordinate of a solution to the system of equations above?

Woops! Forgot part of first equation in question just submitted. Here is the full question:

(x + 2)^2 + (y – 3)^2 = 40
y = -2x + 4

Which could be the x-coordinate of a solution to the system of equations above?

A) √7

B) √35 / 2

C) (6 + 2√34) /5

D) (4 + 2√191) /5

# Could you please explain number 7 on page 29?

Could you please explain number 7 on page 29?

# Can you explain the “mathy” way to do problem 14 on Official Test 10?

Hello!

Can you explain the “mathy” way to do problem 14 on Official Test 10? (I backsolved and got the correct answer, but I wondered if the “official” way to solve it was faster.)

Thanks!

# Hi Mike. I had a question about question 10 on page 218 from your PWN 4th edition Math guide book.

Hi Mike. I had a question about question 10 on page 218 from your PWN 4th edition Math guide book. If percent means divide by 100, why is it 8 x10^-4 instead of 8 x 10^-8? I thought I had to divide 8 x 10^-6 by a 100. Could you clear this up for me?

# On SAT Practice Test 8, I got marked incorrect on Question 7 of the Math No-Calculator section.

On SAT Practice Test 8, I got marked incorrect on Question 7 of the Math No-Calculator section. This is because I said -1 is a valid solution when it isn’t supposed to be. However, if you plug in -1 into the original equation, and say that the square root of 4 is -2, the solution remains true.

So my question is, on the SAT, are you only ever supposed to use the principle square root of numbers? Saying that the square root of 4 = -2 is what rendered my answer incorrect.

# This is a question from April 2018 QAS, Calculator Section, Problem 29.

This is a question from April 2018 QAS, Calculator Section, Problem 29.

I can’t figure out why choice D is the correct answer. I was stuck bw choice A and B, and picked A. Why is A wrong and D correct?

Thank you!

# Hi Mike. I had a question about problem 3 on page 284 of your PWN 4th edition book.

Hi Mike. I had a question about problem 3 on page 284 of your PWN 4th edition book. I don’t understand how you can put values of a, b, c, or d on to the sides. How do you determine which side is which letter?

# On pg. 96 question 11

On pg. 96 question 11 I’m confused with how you came up with your answer even with the explanation. What am I supposed to do there?

# On pg. 96 question 10

On pg. 96 question 10 I’m confused with how you came up with the answer 6, I got the answer -15. How did you come up with 6 I don’t understand?

# On pg. 96 question 9

On pg. 96 question 9 I’m confused with how you came up with the answer 2, I got the answer 4. How did you come up with 2 I don’t understand?