Question

Solve 2x^2
+ x - 4= 0.
x2 +
= 0
DONE

Answer 1

$\\ \sf\longmapsto 2x^2+x-4=0$

$\\ \sf\longmapsto 2x^2+x=4$

$\\ \sf\longmapsto 8(2x^2+x=4)$

$\\ \sf\longmapsto 16x^2+8x=32$

$\\ \sf\longmapsto (4x)^2+2(4x)(1)=32$

$\\ \sf\longmapsto 4x^2+2(4x)(1)+1^2=32+1^2$

$\\ \sf\longmapsto (4x+1)^2=33$

$\\ \sf\longmapsto 4x+1=\pm\sqrt{33}$

$\\ \sf\longmapsto 4x=-1\pm\sqrt{33}$

$\\ \sf\longmapsto x=\dfrac{-1\pm\sqrt{33}}{4}$