Question

Hey, ma puteti ajuta va rog frumos la ex: 15, 16 si 17.
Dau coroana si 50 puncte.
VA ROG ESTE URGENT

Answer 1

poza
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Answer 2

15.a)(97-3)(97+3)=94×100=9400
b)89×111=(100-11)(100+11)=10000-121=99879
c)(68+2)^2=70^2=4900
d)(2012-12)(2012+12)=2000×2024=4048000
e)(47-7)^2=40^2=1600
f)(183-17)(183+17)=166×200=23200
g)(300-4)(300+4)=90000-16
h)(91+9)^2=100^2=10000
i)(2,1-0,1)^2=2^2=4
16a).a+b=4
a-b=2
a^2-b^2=(a+b)(a-b)=4×2=8
b)a-b=5
a^2-b^2=70
2(a+b)=70
a+b=35
17.a arata că Nr sunt pozitive este suficient sa restrângem
a)x^2+2x+1+1=(x+1)^2+1 >0
b)x^2-4x+4+2=(x-2)^2+2>0
d)x^2-8x+16+1=(x-4)^2+1>0
e)4x^2+12x+9+1=(2x+3)^2+1>0
c)9x^2+24x+16+1=(3x+4)^2+1>0
f)25x^2+30x+9+2=(5x+3)^2+2>0