Question

qual o desenvolvimento , dessas equações ?

Answer 1

para a realizacao dessas contas e necessario utilizar a formula de bhaskara:
a)$(2x-1).(x+1)$
$2x^2+2x-x-1$
$2x^2+x-1=0$
$x=-1+/- \sqrt{1^2-4.2.(-1)} /2.2$
$x=-1+/- \sqrt{1+8}/4$
$x=-1+/- \sqrt{9} /4$
$x=-1+/- 3/4$
$\left \{ {{x=-1+3/4=2/4=1/2} \atop {x=-1-3/4=-4/4=-1}} \right.$
b)$(x+3).(3x+3)$
$3x^2+3x+9x+9$
$3x^2+12x+9$
$x^2+4x+3$
$x=-4+/- \sqrt{4^2-4.1.3}/2.1$
$x=-4+/- \sqrt{16-12}/2$
$x=-4+/- \sqrt{4} /2$
$x=-4+/-2/2$
$\left \{ {{x=-4+2/2=-2/2=-1} \atop {x=-4-2/2=-6/2=-3}} \right.$
c)$(x-2).(2x+2)$
$2x^2+2x-4x-4$
$2x^2-2x-4$
$x^2-x-2$
$x=-(-1)+/- \sqrt{(-1)^2-4.1.(-2)}/2.1$
$x=1+/- \sqrt{1+8}/2$
$x=1+/- \sqrt{9}/2$$x=1+/-3/2$
$\left \{ {{x=1+3/2=4/2=2} \atop {x=1-3/2=-2/2=-1}} \right.$
d)$(x-5).(x-5)$
$x^2-5x-5x+25$
$x^2-10x+25$
$x=-(-10)+/- \sqrt{(-10)^2-4.1.25}/2.1$
$x=10+/- \sqrt{100-100} /2$
$x=10+/- \sqrt{0}/2$
nests caso, como delta e igual a zero, ha apenas uma raiz.
$x=10/2=5$
e)$(x+1).(x-10)$
$x^2-10x+x-10$
$x^2-9x-10$
$x=-(-9)+/- \sqrt{(-9)^2-4.1.(-10)}/2.1$
$x=9+/- \sqrt{81+40}/2$
$x=9+/- \sqrt{121}/2$
$x=9+/-11/2$
$\left \{ {{x=9+11/2=20/2=10} \atop {x=9-11/2=-2/2=-1}} \right.$
f)$(2x+1).(x-2)$
$2x^2-4x+x-2$
$2x^2-3x-2$
$x=-(-3)+/- \sqrt{(-3)^2-4.2.(-2)}/2.2$
$x=3+/- \sqrt{9+16}/4$
$x=3+/- \sqrt{25}/4$
$x=3+/-5/4$
$\left \{ {{x=3+5/4=8/4=2} \atop {x=3-5/4=-2/4=-1/2}} \right.$