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?
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
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.
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…)
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. 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:
____
√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
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
PSAT #2, Section 4, #29
PSAT #2, Section 3, #16
PSAT #1, Section 4, #25
PSAT #1, Section 3, #17
PSAT #1, Section 3, #6
