Question

Can someone please help me ? Im trying to factor this equation.
F(x)= (-x)^2 - 10x -3
Dont just give me the answer, i need explanation please. I'm doing a COMPASS test on weds

Answer 1

\[-x^{2}-10x-3 \rightarrow x=5\pm \sqrt{25-3}\]
\[f(x)= (x-5-\sqrt{22})(x-5+\sqrt{22})\]

Answer 2

how do you get the square root of 22 ? Can you make it an easier explanation for me because i first set it up as (x )(x ) and i couldnt figure out the rest because no factors of -3 were equal to the sum -10

Answer 3

is your equation
\[-x^2-10x-3 \] ?

Answer 4

there exists the formula: \[\Delta= \frac{ -\frac{ b }{ 2 }\pm \sqrt{(\frac{ b }{ 2 }})^{2}-ac }{ a }\]
where a,b and c are the numbers in front of x^2, x, and the last term, respectively.

Answer 5

there is a difference between
\[-x ^{2} and (-x)^{2}\]

which do you mean?

Answer 6

Maybe let's assume that it is -x^2 ? since the original poster did say that they couldn't factor ?!

Answer 7

y= -x^2-10x-3

has 2 real roots, but is not factorisable

Answer 8

true @MrNood because when we used the discriminant formula \[b^2-4ac \] letting a = -1, b = -10, and c = -3 we don't have a perfect square

Answer 9

same is true for
y= (-x)^2 - 10x -3

Answer 10

of course we can use the quadratic formula ot get the solution

BUT the OP asks for factorisation

@francemaz
I think your version of the equation is not correct

Answer 11

We have no choice but to use the quadratic formula to get the roots so we can do factorization. Otherwise, what's the alternative? @MrNood

Answer 12

only part of his version is correct. There are sign errors

Answer 13

using the quadratic formula will get the 2 solutions.

This is not 'factorisation' in my understanding of the term

Answer 14

then just leave the problem alone afterwards? are you serious? By the discriminant formula, we either have a perfect square (yes we can factor) or not a perfect square (we have to use the quadratic equation)

Answer 15

given eq can be written as (-x)^2+ 10(-x) -3
now use quadratic formula using -x instead of x and a=1, b= 10 , c=-3,