Answer:

Step-by-step explanation:
1) Rewrite
in the form
, where a = y and b = 1.

2) Use Square of Difference:
.

3) Factor
.
1 - Ask: Which two numbers add up to 6 and multiply to -7?
-1 and 7
2 - Rewrite the expression using the above.

Outcome/Result: 
4) Rewrite the expression with a common denominator.

5) Expand.

6) Collect like terms.

7) Simplify
to 

Answer: The numerator and denominator degrees of freedom (respectively) for the critical value of F are <u>4</u> and<u> 118 .</u>
Step-by-step explanation:
We know that , for critical value of F, degrees of freedom for numerator = k-1
and for denominator = n-k, where n= Total observations and k = number of independent variables.
Here, Numbers of independent variables(k) = 5
Total observations (n)= 123
So, Degrees of freedom for numerator = 5-1=4
Degrees of freedom for denominator =123-5= 118
Hence, the numerator and denominator degrees of freedom (respectively) for the critical value of F are <u>4</u> and<u> 118 .</u>
You're nearly there. Just some more steps.
557 * x = 594 tells us
x = 594 / 557 (divide both sides by 557)
x ≈ 1.066427
When we've found this number we must realise the following:
the '1' in this answer is the 100% the car fixing costs (without taxes)
the '0.66427' stands for the tax rate.
To find the tax rate we multiply 0.66427 by 100, which gives us:
0.66427 * 100 = 6.6427 ≈ 7
So, rounded to the nearest %, the tax rate is 7%