No 20.0000004 cannot be rational.
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Answer:</h2>

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Step-by-step explanation:</h2>
For a better understanding of this problem, see the figure below. Our goal is to find
. Since:

and
is a common side both for ΔMRN and ΔMQN, then by SAS postulate, these two triangles are congruent and:

By Pythagorean theorem, for triangle NQP:

Applying Pythagorean theorem again, but for triangle MQN:

Answer:
17 hours
Step-by-step explanation:
$136/8hr = $17 dollars an hour
$17/hr=$289/t
$17/hr t=$289
t=17 hours
I'm assuming that you meant:
y = 7x² + 3
Remember! Inputs are always x values (unless stated otherwise). Meaning the problem says:
x = 4
y = 7(4)² + 3
The square only applies to the 4. The 7 is not going to be squared! (To be exact it only applies to whatever the value of x is.
4² = 4·4 = 16
Remember:
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction
Follow PEMDAS from left to right (or in the case above from top to bottom).
7·16 + 3 = ?
16·7 = 10·7 + 6·7 = 70 + 42 = 112
(All I did to multiply was break it up into parts. If it confuses you don't worry about it, and just multiply it out like normal or use a calculator if you are allowed to)
112 + 3 = ?
Our output is:
115!
About 455 days
hope this helped