Question

Pentru x=5 si y=3, verificati daca fiecare din urmatoarele egalitati este adevarata:
a.
(x+y) la a doua =x laa doua + y la adoua+ 2xy
b. (x-y) la a doua= x la a doua + y la a doua- 2xy
c.( x+y) (x-y) = x la a doua - y la a doua

Answer 1

*toate sunt formule de calcul*

a.

$(5 + 3) ^{2} = 5 ^{2} + 3 ^{2} + 2 \times 5 \times 3 \\ = 25 + 9 + 30 \\ = 34 + 30 \\ = 74$

b.

$(5 - 3) {}^{2} = 5 {}^{2} + 3 {}^{2} - 2 \times 5 \times 3 \\ = 25 + 9 - 30 \\ = 34 - 30 \\ = 4$

c.(

$(5 + 3)(5 - 3) = 5 {}^{2} - 3 {}^{2} \\ = 25 - 9 \\ = 16$

Answer 2

A.

(x+y)*2=(5+3)*2=25+30+9=55+9=64

B.

(x-y)*2=(5-3)*2=25-30+9=-5+9=4

C.

(x+y)(x-y)=(5+3)(5-3)=25-9=16 sau 8×2=16