Test 4, section 4, question #27. Why is the answer D instead of C? Please explain this.

# The following expression represents the concentration, in microbubbles per milliliter…

The following expression represents the concentration, in microbubbles per milliliter, of the microbubble suspension remaining in a client t seconds after the technician has begun the ultrasound process.

100,000,000 ⋅ 0.5^(t/120)

Which expression shows the multiple of the concentration remaining each minute as a constant or coefficient?

# Thomas is making a sign in the shape of a regular hexagon with 4-inch sides…

Thomas is making a sign in the shape of a regular hexagon with 4-inch sides, which he will cut out from a rectangular sheet of metal. What is the sum of the areas of the four triangles that will be removed from the rectangle?

# After doing some practice problems on Rational Equations on Khan Academy, I was wondering…

After doing some practice problems on Rational Equations on Khan Academy, I was wondering would the equation be undefined if after factoring the equation we obtain cancellable factors on the denominator and the numerator? For ex: ( (2x-1) (x+4) ) / (x+4) would -4 be a plausible argument? I see the x+4 factor can be cancelled together with the one in the numerator.

# There are five houses on each side of a street…

There are five houses on each side of a street, as shown in the figure above. No two houses next to each other on the same side of the street and no two houses directly across from each other on opposite sides of the street can be painted the same color. If the houses labeled G are painted gray, how many of the seven remaining houses cannot be painted gray?

# A marine aquarium has a small tank and a large tank, each containing only red and blue fish…

Here’s a problem from Khan Academy’s SAT practice section. Please explain this one for me.

A marine aquarium has a small tank and a large tank, each containing only red and blue fish. In each tank, the ratio of red fish to blue fish is 3 to 4. The ratio of fish in the large tank to fish in the small tank is 46 to 5. What is the ratio of blue fish in the small tank to red fish in the large tank?

# Number 2 on the functions practice questions

I’m having a lot of trouble with this problem, could you please break it down for me? It is number 2 on the functions practice questions. “If f(x-1)=x+1 for all values of x, which of the following is equal to f(x+1)?”

A. x+3

B. x+2

C. x-1

D. x-3

# In the xy-plane, the point (6,3) is the midpoint of the line segment with endpoints (x,5) and (9,y). What is the value of x+y ?

The midpoint formula tells you that the a segment with endpoints (a, b) and (c, d) will have a midpoint at ((a + c)/2,(b + d)/2) So we know that (x + 9)/2 = 6 and (5 + y)/2 = 3. We can solve those! (x + 9)/2 = 6 x + 9 = 12 x = 3 (5 + y)/2 = 3 5 + y = (more…)

# Practice Test 6 Calculator Section # 29

Practice Test 6 Calculator Section # 29

# Question 11 on the no-calculator math section of Practice Test #4.

Hi!

I wanted to ask for your assistance on an SAT Practice Test question? It’s a question on systems of equations. The question I’m referring to is question 11 on the no-calculator math section of Practice Test #4.

Thank you in advance :’)

# Could you do Test 8 section 4 question 24 for me?

Could you do Test 8 section 4 question 24 for me?

I can’t understand why the answer is D and not C.

# 2x-5y=8 4x+ky=17 For which of the following values of k will the system of equations above have no solution (A)-10 (B)-5 (C)0 (D)5 (E)10

When a system of linear equations has no solution, that means you have parallel lines, which means the lines have the same slope. So put both equations into slope-intercept form (y = mx + b) first: In order for those lines to be parallel, their slopes must be equal, which means 2/5 = -4/k. That means k must be (more…)

# A logarathim question

A logarathim question:

pH = – log h

The pH of a solution is dependent on the concentration of hydronium ions, h, and can be calculated by the equation above. If the concentration of hydronium in solution A is 100 times the concentration of the hydronium in solution B, what is the absolute value of the difference in their pH values?

A. –2

B. 2

C. 3

D. 10

E. 100

# The volume, V, of a right circular cylinder is given by the formula V=πr^2*h, where r is the radius of the base and h is the height of the cylinder. If r is divided by 2 and h is multiplied by 2, the new cylinder’s volume V will be: A) 1/4 the original volume B) 1/2 the original volume C) the original volume D) 2 times the original volume

Just do those things and simplify: Looks like the volume of the second cylinder is half the volume of the first! 🙂 The shortcut here is to recognize that the r value gets squared but the h value doesn’t, so you can say the volume is divided by 4 then multiplied by 2. from Tumblr https://ift.tt/2De8uzO

# If the circumference of the circle with center O is 12π and angle AOB is 60 degree , what is the length of minor arc AB?

60° is 1/6 of the circle (which has 360° of arc in total), so the length of the minor arc will be 1/6 of the circumference. 1/6 of 12π is 2π. from Tumblr https://ift.tt/2JsMj92