Answer:
x = 82°
y = 59°
z = 39°
Step-by-step explanation:
∠x = 1/2(134° + 30°) = 82°
∠z = 180° - 59° - 82° = 39°
arc DF = 2(39°) = 78°
arc DB + arc DF = 134° + 78° = 212°
draw a diameter down from point B to the opposite side of the circle, call that point P:
arc BDP = 180°
(arc BDF) 212° - 180° = 32° (arc PF)
∠PBG = 1/2(32°) = 16°
∠DEB = 1/2(134°) = 67°
∠DBE = 180° - 59° - 67° = 54°
(∠DBE) 54° - (∠z) 39° + (∠PBG) 16° = (∠PBE) 31°
y = 90°- 31° = 59°
Answer: 912
===================================
Work Shown:
The starting term is a1 = 3. The common difference is d = 5 (since we add 5 to each term to get the next term). The nth term formula is
an = a1+d(n-1)
an = 3+5(n-1)
an = 3+5n-5
an = 5n-2
Plug n = 19 into the formula to find the 19th term
an = 5n-2
a19 = 5*19-2
a19 = 95-2
a19 = 93
Add the first and nineteenth terms (a1 = 3 and a19 = 93) to get a1+a19 = 3+93 = 96
Multiply this by n/2 = 19/2 = 9.5 to get the final answer
96*9.5 = 912
I used the formula
Sn = (n/2)*(a1 + an)
where you add the first term (a1) to the nth term (an), then multiply by n/2
-----------------
As a check, here are the 19 terms listed out and added up. We get 912 like expected.
3+8+13+18 +23+28+33+38 +43+48+53+58 +63+68+73+78 +83+88+93 = 912
There are 19 values being added up in that equation above. I used spaces to help group the values (groups of four; except the last group which is 3 values) so it's a bit more readable.
Answer:
b option im not sure but
Step-by-step explanation:
Answer:
Primul copil are 6 lei, al doilea are 12 lei, al treilea are 27 de lei.
Step-by-step explanation:
Lăsați suma primului copil să fie x.
Lăsați suma al doilea copil să fie y.
Lăsați suma al treilea copil să fie z.
Trei dintre ei au 45 de lei în total.
Aceasta înseamnă că:
x + y + z = 45 ________(1)
Al doilea are de două ori valoarea primului:
y = 2x
Al treilea are cu 15 lei mai mult decât al doilea:
z = 15 + y
=> z = 15 + 2x
Puneți valoarea y și z în (1):
x + 2x + 15 + 2x = 45
5x = 45 - 15 = 30
x = 30 / 5 = 6 lei
=> y = 2 * 6 = 12 lei
=> z = 15 + 12 = 27 lei
Primul copil are 6 lei, al doilea are 12 lei, al treilea are 27 de lei.
