Question

please help! Medal and fan
Which of the following cannot be solved using the quadratic formula?
A. -3x^2-x+3 =-3x^2
B. 0=x^2
C. 0=2x^2-1
D. x^2 +3x-2=4x^2-5x-1

Answer 1

check their discriminant
if the discriminant is a negative value, then it has no solution
or two complex roots

http://www.regentsprep.org/regents/math/algtrig/ate3/discriminant.htm

Answer 2

but you need 3 values for a discriminant, a,b,and c. and B. doesnt have all 3. im confused

Answer 3

@jdoe0001

Answer 4

hmmm actually it should be \(\bf A. \quad -3x^2-x+3 =-3x^2\implies \cancel{ -3x^2+3x^2}-x+3 =0
\\ \quad \\
\quad y={\color{blue}{ 0}}x^2{\color{red}{ -1}}x{\color{green}{ +3}}
\qquad \qquad
{{\color{red}{ b}}^2 -4{\color{blue}{ a}}{\color{green}{ c}}}\)

Answer 5

are you saying its a?

Answer 6

nope, I'm saying that all have 3 components
but sometimes one of them may well be 0
lemme rewrite all 4

Answer 7

\(\bf A. \quad -3x^2-x+3 =-3x^2\implies \cancel{ -3x^2+3x^2}-x+3 =0
\\ \quad \\
\quad {\color{blue}{ 0}}x^2{\color{red}{ -1}}x{\color{green}{ +3}}=0\qquad \qquad

\\ \quad \\
% ---------------------

B.\quad 0=x^2\implies 0={\color{blue}{ 1}}x^2{\color{red}{ +0}}x{\color{green}{ +0}}
\\ \quad \\
%----------------------
C.\quad 0=2x^2-1\implies 0={\color{blue}{ 2}}x^2{\color{red}{ +0}}x{\color{green}{ -1}}
\\ \quad \\
%---------------------
D. \quad x^2 +3x-2=4x^2-5x-1
\\ \quad \\
0=4x^2-x^2-5x-3x-1+2\implies 0={\color{blue}{ 3}}x^2{\color{red}{ -8}}x{\color{green}{ +1}}
\\ \quad \\ \quad \\
discriminant\implies \Large {{\color{red}{ b}}^2 -4{\color{blue}{ a}}{\color{green}{ c}}}\)

Answer 8

is it B

Answer 9

@jdoe0001

Answer 10

hmmm what discriminant did you get for B though?

Answer 11

4.

Answer 12

a = 1 b=0 c = 0

\(\bf (0)^2-4(1)(0) \implies ?\)

Answer 13

oops -4

Answer 14

hmmm -4 * 1 * 0 = ?

Answer 15

hint: anything multiplied by 0 is 0

Answer 16

100000 * 99999.999 * 97919849494 * one gazillion * 5 trillions * 0 = 0

Answer 17

omg im sorry lol okay so 0

Answer 18

whats the answer lol :/

Answer 19

@jdoe0001