Hi! For page 120 question 8 in the pwn book, is there any other way to find the answer without using a Calculator? I tried using a calculator but it took me a long time to find the answer. In addition, is there any other way to find that there is only one solution other than graphing or plugging the x values back into the equation?

# In this equation, k is a constant…

Some help please, Mike?

x^2 – 12x +k = 0 In this equation, k is a constant. For which values of k does the equation have only one solution? I know I can set the discriminant to zero and solve for k. But is there another way to solve? Thanks!

# What is the set of all solutions to the equation square root of (x+2)=-x?

What is the set of all solutions to the equation square root of (x+2)=-x

A){-1,2}

B){-1}

C){2}

D)There are no solutions to the given equation

Show your work, or tell me how you got your answer thanks.

# sqrt(3m^2 + 24) = 2m + 2. What is the sum of all the solutions to the equation? I know how to find the sum algebraically, but why can’t I use the -b/a formula here? Is it because there’s a radical? Thank you!

Whenever you have to square both sides to solve, you have to check for extraneous solutions. That tells you m could be 2 or –10, but because part of the solution was squaring both sides, you need to run both possible solutions through the original equation.Try 2 first: That works, now how about –10? Nope. Remember (more…)

# Test 7 Section 4 Question 6

Hi Mike…SAT 7, Section 4, Q6: I now see the shortcut here (that both sides of the equation are perfect squares,) but if I did expand and FOIL the left side, wouldn’t I still get the correct “a” values even though it takes longer? I can’t get it to work !! Can you please show the alternate path math steps? Or is recognizing the perfect squares the ONLY way to solve this one ? Thanks!

# PWN the SAT Math Guide p. 120 #9

PWN the SAT Math Guide p. 122 (p. 120 in newer printing) #9

h = -4.9^2 + t + 1.5

The equation … After how many seconds will the coin land on the ground?

When the coin lands, y=0, so we just need to solve the quadratic. Using the quadratic formula, however, I get a messy repeating decimal, not .664, .665. Could you solve this for me using the quadratic formula?

Also, I tried to search the Q&A here to see if you had already answered this question. Could you make an index for PWN the SAT Math Gu

# College Board Test 4 Section 3 #9

College Board Test 4 Section 3 #9:

____

√x-a = x-4

If a=2 what is the solution set of the preceding equation?

A. {3, 6}

B. {2}

C. {3}

D. {6}

Is there another way to solve this quickly besides plugging in the answer choices?

# Test 6 Section 3 #13

Test 6 Section 3 #13

# What is the set of all solutions to the equation square root of (x+2) = -x?

What is the set of all solutions to the equation square root of (x+2) = -x?

A) (-1,2) B) (-1), C) (2), D) There are no solutions.

Answer is (-1), but why won’t (-1,2) work? Square root of (2+2) = √4 = +/- 2, right?

# Test 8 Section 3 #14

Test 8 Section 3 #14

# PSAT #2, Section 4, #29

PSAT #2, Section 4, #29

# PSAT #2, Section 3, #16

PSAT #2, Section 3, #16

# PSAT #1, Section 4, #25

PSAT #1, Section 4, #25

# PSAT #1, Section 3, #17

PSAT #1, Section 3, #17

# PSAT #1, Section 3, #6

PSAT #1, Section 3, #6