Answer:
y=-2
Step-by-step explanation:
y+3y+5y=−18
Combine like terms
9y = -18
Divide each side by 9
9y/9 = -18/9
y = -2
Step-by-step explanation:
Effective resistance in the 30Ω and 40Ω parallel circuit = 1 / (1/30 + 1/40) = 120/7 Ω.
20Ω + 10Ω = 30Ω
Effective resistance in the 50Ω and (20Ω + 10Ω) parallel circuit = 1 / (1/50 + 1/30) = 75/4 Ω.
Now we can add the resistances up:
Effective resistance for circuit
= 120/7 Ω + 75/4 Ω = 1005/28 Ω.
Hence I = V / R
= 9.0V / (1005/28 Ω) = 0.25A. (2s.f.)
2a
tan37=r/8
r=8tan37
r≈6 in rise per step (to nearest whole inch)
2b
11*12/6=22 steps needed to climb the 11 ft to the entrance
...
3a
tanα=14/20
α=arctan(7/10)
α≈35° (to nearest whole degree)
..
3b
tanα=21/17
α=arctan(21/17)
α≈51° (to nearest degree)
