Answer:
- $70
- y = 25 + 0.9x
- $250
Step-by-step explanation:
1. 10% of $50 is $5, so the purchases would come to $50 -5 = $45. Added to the $25 membership fee, the total cost for the year would be
$45 +25 = $70
2. The member pays $25 even if no purchases are made. Then any purchases are 100% - 10% = 90% of the marked price. So, the total is ...
y = 25 + 0.90x
3. $25 is 10% of $250, so that is the amount the member would have to purchase to break even on cost.
If you like, you can compare the cost without the membership (x) to the cost with the membership (25+.9x) and see where those costs are equal.
x = 25 +0.9x . . . . . x is the spending level at which there is no advantage
0.1x = 25 . . . . . . . . subtract 0.9x
25/0.1 = x = 250 . . . divide by 0.1
Looks like the system is
We can eliminate 
by taking
so that 
, and
Substitute into this last equation and solve for 
:
Then
Plug these values into any one of the original equation to solve for :
Hence the solution is x = 4, y = -3, and z = 2.
Since 16 and 25 are perfect squares you can factor the first part.
4^2-5^2(b+3)^2
=(4-5(b+3))(4+5(b+3))
=(4-5b-15)(4+5b+15)
=(-11-5b)(19+5b)
Which can be expanded if necessary,
= -209+150b-25b^2
Answer:
8 pounds of peanuts, 6 pounds of raisins and 6 pounds of chocolate chips
Step-by-step explanation:
Let x be the number of pounds of peanuts and y be the number of pounds of raisins and chocolate chips.
Peanuts cost $2 per pound, then x pounds cost $2x.
Raisins cost $2.50 per pound, then y pounds cost $2.50y.
Chocolate chips cost $4 per pound, then y pounds cost $4y.
In total, x+y+y=20 and those 20 pounds cost
2x+2.50y+4y=20·2.75.
Solve the system of two equations:
From the first equation:
Substitute x into the second equation:
Answer:
28 inches
Step-by-step explanation:
To begin, the area of a rectangle is base · height. Since we are given one of the sides already, you can make an equation to solve for the other value.
5 · x = 45
5x = 45
x = 9
A rectangle has two pairs of parallel sides, or in easier terms, two sets of sides that are the same. So, the perimeter is going to be two lengths plus two widths.
2 · 5 + 9 · 2 = 10 + 14 = 28
