Question

calculati...Va dau coroana ...

Answer 1

T1

a) se scot in factori parantezele comune

(2x-1)(5x+4)+(5x+4)(2x+5)=(5x+4)(2x-1+2x+5)=(5x+4)(4x+4)=4(5x+4)(x+1)

(5x-3)(x-2)-(5x-3)(x+9)=(5x-3)(x-2-x-9)=-(5x-3)*7

(3x-rad5)^2+(3rad5x+1)^2-(2rad7x-rad5)(2rad7x+rad5)=9x^2-6xrad5+5+45x^2+6rad5x+1-(28X^2-5)=26x^2+12xrad5+10

T2

5a-5b=5(a-b)

(3x-4)(x+7)-(x+7)(2x-5)=(x+7)(3x-4-2x+5)=(x+7)(x+1)

4x^2-49=4x^2-7^2=(2x-7)(2x+7)

9(x+3)^2-4x^2=[3(x+3)-2x][3(x+3)+2x]=(x+9)(5x+9)

5x^2-10x+5=5(x^2-2x+1)=5(x-1)^2

a^2+2a+1-b^2=(a+1)^2-b^2=(a+1-b)(a+1+b).

T3

a-b=1

a^2+a-2ab+b^2-b=(a-b)^2+(a-b)=1+1=2

a+b=2

a^2+b^2+2a+2b+2ab=(a+b)^2+2(a+b)=2^2+2*2=4+4=8