Question

VA ROOG
E URGENTT
imi trebuie până la 21!!!​

Answer 1

Răspuns:

4. a)

a= ( $\sqrt{2} - \sqrt{3}$) ( $2\sqrt{2}$ + 2$\sqrt{3}$ + 3$\sqrt{2}$ + 3$\sqrt{3}$)= ($\sqrt{2} - \sqrt{3}$) *(5$\sqrt{2} + 5\sqrt{3}$)=

a= ( $\sqrt{2} - \sqrt{3}$) *( $\sqrt{2} + \sqrt{3}$) *5= (2 +$\sqrt{6}$ -$\sqrt{6}$ -3) *5 = -1 *5= - 5

a= -5

5. E(x) = 6$x^{2}$ + 9x -4x- 6 -$x^{2}$ +2x-1 - 4$x^{2}$ + 4x -1 + 26=

= $x^{2}$ + 11x -8+26 = $x^{2}$ +11x + 16    x se va inlocui cu 7^{n} +2

E( $7^{n}$+2) = ( $7^{n}$+2)² + 11* ( $7^{n}$+2) +16=  $7^{2n}$+ 4* $7^{n}$ + 4 + 11* $7^{n}$+22 +16=

= $7^{n}$*( $7^{2}$ + 4 +11) + 42= $7^{n}$ *( 49+15) + 6*7¹= $7^{n}$* $8^{2}$ + 6*7¹