Answer:
About 62.1371
Step-by-step explanation:
Given that,
An equation : -9c² +2c +3 = 0
To find,
Find the value of x.
Solution,
We have, -9c² +2c +3 = 0
We can solve it using the formula as follows :

Here, a = -9, b = 2 and c =3
Put the values,

So, the solution are -0.47 and 0.69.
60 minutes for 2 times of 4.5 miles
60 minutes for 9 miles.
9 miles/60 minutes = 9 miles/1 hour
9 mph
Answer:

Step-by-step explanation:
<u>Rational Numbers</u>
A rational number is any number that can be expressed as a fraction

for a and b any integer and b different from 0.
As a consequence, any number that cannot be expressed as a fraction or rational number is defined as an Irrational number.
Let's analyze each one of the given options

The first part of the number is indeed a rational number, but the second part is a square root whose result cannot be expressed as a rational, thus the number is not rational

The second part is an exact square root (resulting 4) but the first part is a known irrational number called pi. It's not possible to express pi as a fraction, thus the number is irrational

The square root of 121 is 11. It makes the whole number a sum of a rational number plus an integer, thus the given number is rational

As with the first number, the square root is not exact. The sum of a rational number plus an irrational number gives an irrational number.
Correct option:

Given that f(x) = ax – 5 and f(4) = 15, then the value of a is 5
The given function is:
f(x) = ax - 5
If f(4) = 15, then x = 4
Substitute x = 4 into f(x) = ax - 5
f(4) = a(4) - 5
15 = 4a - 5
Solve for a by adding 5 to both sides
15 + 5 = 4a - 5 + 5
20 = 4a
Divide both sides by 4
4a/4 = 20/4
a = 5
Given that f(x) = ax – 5 and f(4) = 15, then the value of a is 5
Learn more on linear functions here: brainly.com/question/15602982