Answer:
The price of the cell phone without the coupon= $500
Step-by-step explanation:
Step 1: Express discounted amount
The discounted amount can be expressed as a function of the original cost of the phone as follows;
D=r×A
where;
D=discounted amount
r=coupon rate
A=original price of the cell phone before the coupon
In our case;
r=45%=45/100=0.45
A=a
replacing;
Discounted amount=(0.45×a)=0.45 a
Step 2: Amount she pays up
Amount she pays=Original cost of cell phone-discounted amount
where;
Amount she pays= $275
original cost of cell phone=a
discounted amount=0.45 a
replacing;
$275=a-0.45 a
0.55 a=275
a=275/0.55
a=500
The price of the cell phone without the coupon= $500
Answer: y=−5/4x−5
Step-by-step explanation:
DI/dx=-850x+45500
d2l/d2x=-850 so when dl/dx=0 it is an absolute maximum for l(x)...
dl/dx=0 only when:
850x=45500
x=53.53
x=54 years of age (rounded)
Answer:
A. 63 degrees
Step-by-step explanation:
Complementary angles are angles that add up to 90 degrees. You can make an equation to solve for angle N:
27 + x = 90
rearrange the equation:
90 - 27 = x
63 = x
<span>the sum of the first and three times the second is 54.
x + 3y = 54
3y = 54 - x
y= 54 /3 - x / 3 = 18 -x /3
</span>xy = x (18 -x /3) = 18x - x^2 / 3 = - 1/3 x ^ 2 + 18 x
<span>
</span><span>since a<0, it is concave downward, and the vertex is the maximum value. That vertex occurs at x= - b /2a = (-18) / (-2/3) = 12
</span>
<span>The first number is x=12.
The second is y = </span><span>18 -x /3 = 18- 12/ 3 = 18 - 4 = 14 </span>
