Answer:
tex]a^2 - 4b \neq 2[/tex]
Step-by-step explanation:
We are given that a and b are integers, then we need to show that 
Let 
If a is an even integer, then it can be written as 
, then,
RHS is a fraction but LHS can never be a fraction, thus it is impossible.
If a is an odd integer, then it can be written as 
, then,
RHS is a fraction but LHS can never be a fraction, thus it is impossible.
Thus, our assumption was wrong and .
Answer:
a) The marginal cost function is given by
C'(x) = 4 + 0.04x + 0.0003x² (in dollars)
b) C'(70) = $8.27
Step-by-step explanation:
C(x) = 1000 + 4x + 0.02x² + 0.0001x³
a) Marginal cost is usually defined as the cost of producing one extra unit of product. It expresses how much the total cost is changing with respect to number of units of product.
Mathematically,
MC = (dC/dx) = C'(x)
For this question,
C'(x) = 4 + 0.04x + 0.0003x²
b) C'(70) means the marginal cost at x = 70 units, that is, how much the total cost is changing after the production of 70 units; the cost of producing one extra unit of product after producing 70 units.
C'(x) = 4 + 0.04x + 0.0003x²
C'(70) = 4 + 0.04(70) + 0.0003(70²)
C'(70) = $8.27
Hope this helps!
Multiply both sides of the second equation by 100 to get rid of the decimals:
0.05<em>n</em> + 0.10<em>d</em> = 1.50
==> 5<em>n</em> + 10<em>d</em> = 150
Multiply both sides of the first equation by -5:
<em>n</em> + <em>d</em> = 21
==> -5<em>n</em> - 5<em>d</em> = -105
Add the two equations together:
(5<em>n</em> + 10<em>d</em>) + (-5<em>n</em> - 5<em>d</em>) = 150 + (-105)
Notice that the terms containing <em>n</em> get eliminated and we can solve for <em>d</em> :
(5<em>n</em> - 5<em>n</em>) + (10<em>d</em> - 5<em>d</em>) = 150 - 105
5<em>d</em> = 45
<em>d</em> = 45/5 = 9
Plug this into either original equation to solve for <em>n</em>. Doing this with the first equation is easiest:
<em>n</em> + 9 = 21
<em>n</em> = 21 - 9 = 12
So Donna used 12 nickels and 9 dimes.
