Question

Mă poate ajuta cineva? Dau coroană

Answer 1

13.

3 - 2x = 11 ⇒ 3 - 11 = 2x ⇒ -8 = 2x ⇒ x= - 8:2⇒ x = - 4

14.

6 robinete..............................2 ore (120 min)

4 robinete..............................x ore (...min)

x= (4×120)/6

x= 480/6

x= 80 min ( 1h si 20 min)

15.

Aria rombului cand se cunosc diagonalele= semiprodusul diagonalelor

A=(15 ×11):2=82,5 cm²

16.

mg=√9×16=√144 = 12

17.$aria=\frac{a^{2}\sqrt{3}}{4}$

$aria=\frac{a^{2}\sqrt{3}}{4} =\frac{36\sqrt{3}}{4}=9\sqrt{3}$

18.

2x-3<5 ⇒ 2x < 5 + 3⇒ 2x < 8 ; x < 8/2 ; x < 4

deci x∈ (-∞,4)

19. latura = 3 cm

Perimetrul = 4 × 3 = 12 cm

20.

x = (√3 -1 )²+2√3 = 3 -2√3 +1 + 2√3 = 4

y = (√5-2)(√5+2)+2016° iar 2016° = 1

y = (√5)² -2²= 5 - 4 + 1 = 2

Ma = (x + y)/2 = (4 +2 ) / 2 = 6/2 = 3

Answer 2

13. -2x=8 => x=-4
14. 6 robinete.....2 ore
4 robinete............x
x=(4*2)/6=8/6=4/3 ore
15. A=d1*d2/2=15*11/2=165/2 cm²
16.mg=√9*16=√144=12
17. A=(l²√3)/4=36√3/4=9√3
18. 2x<8
x<4 => x€(-infinit, 4)
19. P=4*l=4*3=12 cm
20. x=3-2√3+1+2√3=4
y=5-4+1=2
ma=(x+y)/2=6/2=3