Question

DAU 60 puncte!!!!!!
Ajutatima va rog!!!!! Ex 4 pag 97 ( clasa 7 )
Amplificati raportul algebric:

b) x+√7 / x-√7 cu x+√7
c) x-y / 3x-y cu 3x+y
d) 4x-y / y+4x cu y+4x

Answer 1

Răspuns:

Explicație pas cu pas:

$\dfrac{^{x+\sqrt{7})}x+\sqrt{7} }{x-\sqrt{7}} = \dfrac{(x+\sqrt{7})^{2}}{(x-\sqrt{7})(x+\sqrt{7})} = \dfrac{x^{2} + 2x\sqrt{7} + 7}{x^{2} - 7}$

$\dfrac{^{3x+y)}x-y}{3x-y} = \dfrac{(x-y)(3x+y)}{(3x-y)(3x+y)} = \dfrac{3x^{2}+xy-3xy-y^{2}}{(3x)^{2}-y^{2}} = \dfrac{3x^{2}-2xy-y^{2}}{9x^{2}-y^{2}}$

$\dfrac{^{y+4x)}4x-y}{y+4x} = \dfrac{(4x-y)(4x+y)}{(y+4x)(y+4x)} = \dfrac{(4x)^{2}-y^{2}}{(4x+y)^{2}} = \dfrac{16x^{2}-y^{2}}{16x^{2}+8xy+y^{2}}$