Answer:
x=3 and x=-1.25
Step-by-step explanation:
4x^2-7x=15
subtract 15 from each side:
4x^2-7x-15=0
factor (trying different numbers that the sum is 7 and the quotient is 15)
(2x-6 )(2x+2.5 )=0
2x-6=0 add 6 to each side
2x=6
x=3
2x+2.5=0 subtract 2.5 from each side
2x=-2.5
x=-1.25
Answer:
150.51 dB
Step-by-step explanation:
Data provided in the question:
decibel level of sound at 161 km distance = 180 dB
d₁ = 161 km
d₂ = 4800 km
I₁ = 180 db
The formula for intensity of sound is given as:
I = 
and the relation between intensity and distance is given as:
I ∝ 
or
Id² = constant
thus,
I₁d₁² = I₂d₂²
or

therefore,
I = 
or
I = 
or
I = 20 × (-1.474)
or
I = -29.49
Therefore,
the decibel level on Rodriguez Island, 4,800 km away
= 180 - 29.49
= 150.51 dB
There are 7,920 minutes in 5.5 days
60minutes in an hour
24hours in a day
60 times 24 times 5.5 = 7,920
Answer:
Unknown
Step-by-step explanation:
Hi! so you didn't add the ordered pair options but I will do my best :) so if you see the ordered pair (0.7) that could definitely be a solution because using the slope intercept form equation you gave I know that's our y Intercept. the slope is 4/1 so moving up 4 and to the right 1 or down 4 and to the left 1 on a graph could show you more points! If you don't want to draw it you could use Desmos and just put this equation in or give me the ordered pairs and I will give you your answer!
hope this helps :)
Answer:
Step-by-step explanation:
22 + 42 divided by 22
we always to division and multiplication before adding or subtracting, so
(42/22) + 22 = a very lonnggg number = 23.9090909091?????
are you sure the equation is correct?
i can help you
thank you