x squared+x-20=?

x^2 + x - 20

(x - 5) (x + 4)

x - 5 = 0

x = 5

x + 4 = 0

x = -4

Solution set : (5. -4)

since that is a simple trinomial and not a perfect square trinomial

the standard equation is x^2 + bx +C...

where B= 1 and C= -20 since your equation is X^2+x-20

next step

Find the number that would satisfy the following

U *V = C

U + V = B

where U and v are real numbers

by trial and error we will arrive at

-4 and 5

because it satisfies the following

(-4) * (5) = -20

-4 + 5 = 1

thus the factor of the trinomial X^2 + X + 20 =

(x-4) * (x+5)

since x is a variable..... the value of the trinomial depends upon the value you substitute with the variable X

so assuming that x=1

then the value of the trinomial will become

1^2 +1 -20..

= 2-20...

= - 18

x^2 + x - 20 =(x + 5) (x - 4)

Which factors of -20, add up to +1?

-20 = (-4)(5)

&

5 - 4 = 1

So, the expression factors as follows:

(x + 5)(x - 4)

Use FOIL to check.

x^2+x-20

(x+5)(x-4)

x=-5 or 4

x^2 + x - 20 = 0

(x - 4) (x + 5) = 0

then x1 = 4 and x2 = -5

(x + 5)(x - 4) = ?

the ? usually represents an unknown y that varies with x.

in this case we can say that when y = 0 the curve cuts the x axis at x = -5 and 4.

you could also differentiate the fist equation x^2 + x - 20 to find the stationary points...

dy/dx = 2x + 1

when dy/dx = 0; x = -0.5

i could go on... but im boring myself

(x+5)(x-4)

x^2 + x - 20 = 0

(x + 5)(x - 4) = 0

x + 5 = 0, x = - 5

x - 4 = 0, x = 4

Answer: x is either - 5 or 4

The answer could take virtually any value, depending on the value of x.