First multiply all terms by z
8-z^2=4z
Then order into standard form
-z^2-4z+8=0
Multiply the equation by -1
z^2+4z-8=0
Plug into quadratic equation
-4±√16-4(-8)
-4±√48
(-4±4√3)/2
-2±2√3
Final answer: z=-2± 2√3
For number 1, it says based on the first two clues, so you would still include the even numbers ranging from 70-81. Then for number 2 we would use clue C because it gives us the most information about our number.
The answer would be C) P,D and A
Irrational will be the answer
There are two equation:
1) From Kim
2) From Daniel
Let:
x be the cost of rolls of plain wrapping paper
y be the cost of rolls of shiny wrapping paper
Kim:
7x + 8y = 140
Daniel:
14x + 7y = 154
<u>Using elimination method:</u>
(7x + 8y = 140) * -2 (Multiplying the equation by -2)
-14x - 16y = -280
-14x -16y = -280
14x + 7y = 154
------------------------------
0x - 9y = -126
9y = 126 (Negative sign cancels from both sides)
y = 126 /9
y = 14
The cost of each shiny wrapping paper is $14.
Now solve x, you pick any two equation to solve for x.
7x + 8y = 140
7x + 8(14) = 140 (You know from above y =14)
7x + 112 = 140
7x = 28
x = 28/7
x = 4
The cost of each plain wrapping paper is $4.
Solution: (4,14)
