help?
Find the value of the discriminant for each quadratic equation below. Show all steps needed to write the answer in simplest form, including substituting the values of a, b, and c in the discriminant formula. Then use the value to determine how many real number solutions each equation has. 5x^2 + x = 4
HI!!
Hey :)
start by setting it equal to zero go from \[5x^2 + x = 4\] to \[5x^2+x-4=0\]
\[\large \color{red}ax^2+\color{blue}bx+\color{green}c=0\] \[\huge \color{red}5x^2+\color{blue}1x+\color{green}{-4}=0\]
then as @risn said compute \[\huge \color{blue}b^2-4\times \color{red}a\times \color{green}c\]
D= 1 - 4 (1)(-4)?
nope
\(\color{red}a=\color{red}{5}\)
oh sorry. D = 1-4(5)(-4)
yeah that is right what do you get?
81?
as my final answer?
yeah me too
at the end of the question it asks us "Then use the value to determine how many real number solutions each equation has".
that is the answer to Show all steps needed to write the answer in simplest form, including substituting the values of a, b, and c in the discriminant formula.
ok two steps here 81 is positive, so there are two real solutions also 81 is a "perfect square" it is the square of 9 that means both solutions are rational numbers
oh ok! thank u so much! :)
in fact that means \[5x^2+x-4=0\] can be solved by factoring you get \[(5x-4)(x+1)=0\] so \[x=\frac{4}{5}\] or \[x=-1\]
\[\color\magenta\heartsuit\]
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