Find f(5). f(x) = x2 +2x

f(5) = 35

Step-by-step explanation:

In any function f(x), x is the input and f(x) is the output

Example:

f(x) = 2x + 3, find f(a)

That means we need to find value of f(x) at x = a, so substitute x by a

f(a) = 2(a) + 3 = 2a + 3

f(a) = 2a + 3

Let us use the same way to solve our question

∵ f(x) = x² + 2x

→ We need to find f(5), so substitute x by 5

∴ f(5) = (5)² + 2(5)

∴ f(5) = 25 + 10

→ Do addition

∴ f(5) = 35

we need more info to solve this

he spend 5.1 minutes chatting with his friends.

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5.1