You simply divide 3 into 8, which results in 0.375. Now you add 7 to it, which is 7.375.
Answer:
v = 15 miles / hour
Step-by-step explanation:
Given:
Distance covered by biker = s=45 miles
time taken by him = t=180 minutes
TO Find:
speed in miles per hour = v = ?
Solution:
As it is given that the distance covered is 45 miles
and time taken by him is 180 minutes
as one hour have 60 minutes
so time taken by rider = t = 180 /60
= 3 hours
this step is done because we have to find speed in miles per hour
Now
The formula for finding the distance is
distance = speed * time
or
s = v * t
we have to find v
so dividing both sides by t

it becomes

Putting the values

solving it gives
v = 15 miles / hour
which is the required speed
in the given options it is not available
Answer:
x= -5
Step-by-step explanation:
just use a calculator
Answer:
n= 21
c= 3x
Step-by-step explanation:
The expression is given as;
(3x⁷)⁴
Apply the brackets law of indices which states that :
If a term with a power is itself raised to a power then the powers are multiplied together
(xᵃ)ᵇ = xᵃˣᵇ
Applying the same;
(3x⁷)⁴ = 3x²¹
If 3x²¹ = c^n
Then n = 21
and
c= 3x
We can factor by grouping. To do so, we multiply the leading coefficient with the constant at the end. In other words, a times c (ax^2 + bx + c).
15*-4 = -60
Now we need to split the b term into two pieces that multiply to -60 and add to 4.
-6 and 10 will work.
Now group one part of b with the 15x^2 and the other part with -4.
(15x^2 + 10x) + (-6x - 4)
Now factor both terms.
5x(3x+2) - 2(3x+2)
3x+2 is one of our factors and 5x-2 is the other.
(3x+2)(5x-2)=0
Now just find the zeros.
3x+2 = 0
3x = -2
x = -2/3
And
5x-2 = 0
5x = 2
x = 2/5
So the answer is x = -2/3 and x = 2/5