Answer:
6
Step-by-step explanation:
Cost per item is found by dividing the cost by the number of items. If the woman bought n items for $120, the cost of each item is $120/n. If the woman bought 24 more items, n+24, at the same price, then the cost per item is $120/(n+24). The problem statement tells us this last cost is $16 less than the first cost:
120/(n+24) = (120/n) -16
Multiplying by n(n+24) gives ...
120n = 120(n+24) -16(n)(n+24)
0 = 120·24 -16n^2 -16·24n . . . . . . subtract 120n and collect terms
n^2 +24n -180 = 0 . . . . . . . . . . . . . divide by -16 to make the numbers smaller
(n +30)(n -6) = 0 . . . . . . . . . . . . . . factor the quadratic
The solutions to this are the values of n that make the factors zero: n = -30, n = 6. The negative value of n has no meaning in this context, so n=6 is the solution to the equation.
The woman bought 6 items.
_____
Check
When the woman bought 6 items for $120, she paid $120/6 = $20 for each of them. If she bought 6+24 = 30 items for the same money, she would pay $120/30 = $4 for each item. That amount, $4, is $16 less than the $20 she paid for each item.
The answer to the selected problem is: that is a linear equation.
To find the total cost, you need to add these numbers together
you get 7.37 as your answer, but you need to round this to the nearest whole number.
rounding 7.37 will make it 7.
the total cost is about $7
Answer:
P = (21.4a+36.6) cm
Step-by-step explanation:
Given that,
The width of a rectangle, b = (6.9a+8.5) cm
The length of a rectangle, l = (3.8a+9.8) cm
We need to find the perimeter of the rectangle. Perimeter is the sum of all sides. So,
P = 2(l+b)
Put all the values,
P = 2(6.9a+8.5+3.8a+9.8)
= 2(6.9a+3.8a+8.5+9.8)
= 2(10.7
a+18.3)
= (21.4a+36.6)
So, the perimeter of the rectangle is (21.4a+36.6) cm.
