Question

Testul 2 va rog din suflet ❤, e URGENT!! , Dau coroana + 38 punctee

Answer 1

1)
a)
3a-4b+a-b=4a-5b
b)
(3x^3)^2:(-x)^2=9x^6:x^2=9x^(6-2)=9x^4
c)
(x+3y)(2x-5y)=2x^2+6xy-5xy-15y^2
2)
(x^2+1)(3x-1)=3x^3-x^2+3x-1
(2x)^2(3x-2)=4x^2(3x-2)=x^2(12x-8)=12x^3-8x^2
7x(3x^2+3)=7x*3(x^2+1)=21x(x^2+1)=21(x^3+x)=21x^3+21x
(3x^3-x^2+3x-1)-(12x^3-8x^2)=-9x^3+7x^2+3x-1
(-9x^3+7x^2+3x-1)+(21x^3+21x)=12x^3+7x^2+24x-1
3)
2a+b=2(1)
Din (1)*2
4a+2b=4(2)
Din (1)*3
6a+3b=6(3)
Din (3)^2
(6a+3b)^2=36(4)
Din (1)*4
8a+4b=8(5)
Dn (5)^3
(8a+4b)^3=512(6)
Din (2)+(4)+(6)
(4a+2b)+(6a+3b)^2+(8a+4b)^3=552
4)
(-x)(2x+1)=-2x^2-x
3(2-x^2-x)=-3x^2-3x+6
(4x^2+2x-3)-(-2x^2-x)=6x^2+3x-3
(6x^2+3x-3)+(-3x^2-3x+6)=3x^2+3
3x^2+3=3(x^2+1)
Cum x^2>=0
x^2+1>=1
3(x^2+1)>=3
Deci pozitiv
5)
5-4x^2
Maximul are loc cand 4x^2=0
x^2=0
x=0
Valoarea maxima se obtine pentru x=0
6)
P=4l
l=(4xy^2z^4):4=xy^2z^4
A=l^2
A=(xy^2z^4)^2=x^2y^4z^8