Question

Tema la matematica exercitiile: 9,11,12,14

Answer 1

Trebuie sa ne folosim de formulele urmatoare:
(a+b)²=a²+2ab+b²
(a-b)²=a²-2ab+b²
a²-b²=(a+b)(a-b)

9)
a) √2²+2√6+√3²+1-2√6+√6²=2+2√6+3+1-2√6+6=12
b)√6²-2√6+1-(√2²-2√6+√3²)=6-2√6+1-2+2√6-3=2
c)√7²+6√14+(3√2)²+3²-6√14+√14²=7+6√14+18+9-6√14+14=48
d)(2√3)²-4√15+√5²-(√15²+4√15+2²)=12-4√15+5-15-4√15-4= - 2

11) 
a) 9x²+12x+4+x²-5²=10x²+12x+4-25=10x²+12x-21
b) 16x²-8x+1-x²+3²=15x²-8x+1+9=15x²-8x+10
c) 5²-16x²+16x²-24x+9=34-24x
d) 2²-49x²+36x²-12x+1=5-13x²-12x
e) 2x²-1-(49x²-42x+9)=2x²-1-49x²+42x-9=-47x²+42x-10
f) 16x²+40x+25-(16-5x²)=16x²+40x+25-16+5x²=21x²+40x+9

12)
a) 4x²+4x+1+9x²+12x+4=13x²+16x+5
b) 9x²-6x+1-(16x²+16x+4)=9x²-6x+1-16x²-16x-4=-7x²-22x-3
c) 16-40x+25x²-(49x²-42x+9)=16-40x+25x²-49x²+42x-9=24x²+2x+7
d) 49x²+28x+4-(16x²-24x+9)=49x²+28x+4-16x²+24x-9=33x²+52x-5
e) 49x²+56x+16+4x²-12x+9=53x²+44x+25
f) 81x²-36x+4-(49-70x+25x²)=81x²-36x+4-49+70x-25x²=56x²+34x-45

14)
a) (x+3)²
b) (x-2)²
c) (x+4)²
d) (4x-2)²
e) (3x-1)²
f) (4x²+1)²
g) (5x+1)²
h) (7x-2)²
i) (8x-5)²