Answer:
the Expression is :
(3) × (1 + 6d + 7y)
Step-by-step explanation:
here's the solution : -
=》

=》

now, since 3 is common in all terms let's take it out.
=》

=》so, ,we got the above expression as product of 3 and ( 1 + 6d + 7y ) as factors.
C ) price Decrease and quantity decrease
<u>Methods to solve rational equation:</u>
Rational equation:
A rational equation is an equation containing at least one rational expression.
Method 1:
The method for solving rational equations is to rewrite the rational expressions in terms of a common denominator. Then, since we know the numerators are equal, we can solve for the variable.
For example,

This can be used for rational equations with polynomials too.
For example,

When the terms in a rational equation have unlike denominators, solving the equation will be as follows



Method 2:
Another way of solving the above equation is by finding least common denominator (LCD)

Factors of 4: 
Factors of 8: 
The LCD of 4 and 8 is 8. So, we have to make the right hand side denominator as 8. This is done by the following step,

we get,

On cancelling 8 on both sides we get,

Hence, these are the ways to solve a rational equation.
Answer:
Yes, the bill is absolutely accurate
Step-by-step explanation:
Cost of materials= $ 678.12
Final bill amount(given)=$1206.12
Rate= $32 per hour for 16.5 hrs
Total amount for 32 hrs = time * rate = 16.5* 32=$528
Therefore, by the problem ,
<em>Cost of materials+ Total amount for 32 hrs = Final bill amount</em>
= 678.12+ 528
=1206.12
<u>Therefore , the final bill amount is 100% accurate as it completely matches with the given bill amount</u>