Question

Ajutor va rog urgent,tot testul

Answer 1

Răspuns:

1.

a)x=13

b)x=2

c)x=(-3)

2.

x^2 + 8x + 15 + 1 - 2x + x^2 = 2(9 - x^2) + 4x^2 - 4x + 1 + 7

2x^2 + 6x + 16 = 18 - 2x^2 + 4x^2 - 4x + 8

6x+16=-4x+26

10x=10 =>x=1

3.

9x^2 + 6x + 1 - 4 = 0

9x^2 + 6x - 3 = 0 |:3

3x^2 + 2x - 1 = 0

delta=4+12=16 =>rad.delta=4

x1=(-2-4)/6=(-1)

x2=(-2+4)/6=1/3

4.

x+15=31 =>x=16

5.

a+b=59

b=a+11

a+a+11=59

2a=48 =>a=24 =>y=35

6.

561 lei _________ 85%

x lei ___________ 100%

x=56100/85=660 lei

660 lei _________ 110%

y lei ____________ 100%

y=6600/110=660/11=600 lei preț inițial