Answer: 2x/5 - 3/5
Step-by-step explanation: Simplify the expression.
Hope this helps you out. Good luck! ☺
-Leif Jonsi-
X + y = 20
xy = -3
x + y = 20
x - x + y = -x + 20
y = -x + 20
xy = -3
x(-x + 20) = -3
x(-x) + x(20) = -3
-x² + 20x = -3
-x² + 20x + 3 = 0
-1(x²) - 1(-20x) - 1(-3) = 0
-1(x² - 20x - 3) = 0
-1 -1
x² - 20x - 3 = 0
x = -(-20) ± √((-20)² - 4(1)(-3))
2(1)
x = 20 ± √(400 + 12)
2
x = 20 ± √(412)
2
x = 20 ± 2√(103)
2
x = 10 ± √(103)
x = 10 + √(103) or x = 10 - √(103)
x + y = 20
10 + √(103) + y = 20
- (10 + √(103)) - (10 + √(103))
y = 10 - √(103)
(x, y) = (10 + √(103), 10 - √(103))
or
x + y = 20
10 - √(103) + y = 20
- (10 - √(103)) - (10 - √(103))
y = 10 + √(103)
(x, y) = (10 - √(103), 10 + √(103))
The two numbers that add up to 20 and multiply to -3 are 10 ± √(103).
Represent
r=number of rabbits
c=number of chickens
1 rabbit=4 feet and 1 head
1 chicen=2 feet and 1 head
rabbits head+chicen heads=72
1r+1c=72
feet=200
4 times r+2 times c=200
4r+2c=200
divide both sides by 2
2r+c=100
we have
r+c=72
2r+c=100
make first equation negative and add to second equation
-r-c=-72
<u>2r+c=100 +
</u>1r+0c=28
r=28
subsitute
r+c=72
28+c=72
subtract 28
c=44
44 chickens and 28 rabits
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Answer:
y=-x+3
Step-by-step explanation:
Answer:
x = 5 (see below)
Step-by-step explanation:
Combine like terms by subtracting on both sides:
25 + 8x = 5 + 12x
20 = 4x
Then divide:
20 = 4x
5 = x
Move the variable to the left side of the equation:
x = 5