(f∘g)(x) is equivalent to f(g(x)). We solve this problem just as we solve f(x). But since it asks us to find out f(g(x)), in f(x), each time we encounter x, we replace it with g(x).

In the above problem, f(x)=x+3.

Therefore, f(g(x))=g(x)+3.

⇒(f∘g)(x)=2x−7+3

⇒(f∘g)(x)=2x−4

Basically, write the g(x) equation where you see the x in the f(x) equation.

f∘g(x)=(g(x))+3 Replace g(x) with the equation

f∘g(x)=(2x−7)+3

f∘g(x)=2x−7+3 we just took away the parentheses

f∘g(x)=2x−4 Because the −7+3=4

This is it

g∘f(x) would be the other way around

g∘f(x)=2(x+3)−7

now you have to multiply what is inside parentheses by 2 because thats whats directly in front of them.

g∘f(x)=2x+6−7

Next, +6−7=−1

g∘f(x)=2x−1

Its a lts easier than you think!

Hope this helped

5 0

4 years ago

A motorboat travels 244 kilometers in 4 hours going upstream and 749 kilometers in 7 hours going downstream. What is the rate of

Kryger [21]

Answer:

Speed of Motorboat = 84 kmph

Speed of Current = 23 kmph

Step-by-step explanation:

Distance Equation is:

D = RT

Where

D is distance

R is rate

T is time

Downstream rate is rate of boat PLUS current

Upstream rate is rate of boat MINUS current

Let rate of boat be "x" and rate of current be "c".

From first statement, we can write:

244 = (x - c)(4)

From second statement, we can write:

749 = (x + c)(7)

The first equation becomes:

244 = 4x - 4c

The second equation becomes:

749 = 7x + 7c

Multiplying first equation by 7 , we have:

7 * [244 = 4x - 4c] = 1708 = 28x - 28c

Multiplying 2nd equation by 4, we have:

4 * [749 = 7x + 7c] = 2996 = 28x + 28c

Now we add up these equations (in bold):

1708 = 28x - 28c

2996 = 28x + 28c

----------------------------

4704 = 56x

x = 4704/56

x = 84

Now using this value and plugging in original equation, we can find "c":

244 = 4x - 4c

244 = 4(84) - 4c

244 = 336 - 4c

4c = 92

c = 92/4

c = 23

<u>Speed of Motorboat = 84 kmph</u>

<u>Speed of Current = 23 kmph</u>

6 0

3 years ago