Răspuns :
*toate sunt formule de calcul*
a.
[tex](5 + 3) ^{2} = 5 ^{2} + 3 ^{2} + 2 \times 5 \times 3 \\ = 25 + 9 + 30 \\ = 34 + 30 \\ = 74[/tex]
b.
[tex](5 - 3) {}^{2} = 5 {}^{2} + 3 {}^{2} - 2 \times 5 \times 3 \\ = 25 + 9 - 30 \\ = 34 - 30 \\ = 4[/tex]
c.(
[tex](5 + 3)(5 - 3) = 5 {}^{2} - 3 {}^{2} \\ = 25 - 9 \\ = 16[/tex]
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