Question 80815
x^2 = -5x + 8
:
I'm not sure what you have got here, the above equation will not factor, anyway,
put in the ax^2 + bx + c = 0 form.
x^2 = -5x + 8
:
x^2 + 5x = 8; added 5x to both sides
x^2 + 5x - 8 = 0; subtracted 8 from both sides
:
There are no integer factors so use the quadratic formula:
Here it is step-by-step:
In this equation a = 1; b = 5; c = -8
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
{{{x = (-5 +- sqrt( 5^2-4*1*-8 ))/(2*1) }}}
{{{x = (-5 +- sqrt( 25 -(-32) ))/(2) }}}
{{{x = (-5 +- sqrt( 25 + 32 ))/(2) }}}
{{{x = (-5 +- sqrt( 57 ))/(2) }}}
{{{x = (-5 +- 7.55)/(2) }}}
Two solutions:
{{{x = (-5 + 7.55)/(2) }}}
{{{x = (+2.55)/(2) }}}
x = +1.275
and
{{{x = (-5 - 7.55)/(2) }}}
{{{x = (-12.55)/(2) }}}
x = -6.276
:
:
Are these supposed to be other problems; Let me know, and what you need help
with.
:
(x+3)(x+4)=0
x=-3
x^2=16
x^2=16=0