Question

E(x)=(2x+1)la patrat-2(x-1)la patrat+(1-x)(x+3)
Aratati ca: E(x)=(x+3)la patrat -7

Answer 1

${(2x + 1)}^{2} - 2 {(x - 1)}^{2} + (1 - x)(x + 3)$

$= 4 {x}^{2} + 4x + 1 - 2( {x}^{2} - 2x + 1) + (x + 3 - {x}^{2} - 3x)$

$= 4 {x}^{2} + 4x + 1 - 2 {x}^{2} + 4x - 2 + x + 3 - {x}^{2} - 3x$

$= {x}^{2} + 6x + 2$

[tex]{(x+3)}^2-7={x}^{2}+6x+9-7={x}^{2}+6x+2