Answer:
Step-by-step explanation:
1.
c+9=±8
either c=8-9=-1
c=-8-9=-17
so c=-1,-17
D
2.
8x^2-3=2
8x^2=5
so A
3.
so D
or
Answer:
70
Step-by-step explanation:
By exterior angle theorem:
distance is speed multiply by time, from speed equals distance divided by time so we have 100 multiply by 6 which is 600km
Number of zids=x
number of zods=y
number of zid legs=5x
number of zod legs=7y
so
5x+7y=140
try to get it into slope intercept from so you can graph is (y=mx+b)
5x+7y=140
subtract 5x from both sides
7y=140-5x
divide both sides by 7
y=20-5/7x
y=-5/7x+20
plug in numbers for x and get numbers for y (you can only plug in multiples of 7 for x so that there are a whole number of zids and since you are counting, x and y must never be negative)
lets try 0 for x
y=-5/7(0)+20
y=20
so x=0 and y=20 is an answer (if you can have only one of that species)
lets try 7 for x
y=-5/7(7)+20
y=-5+20
y=15
so x=7 and y=15 is an answer
lets try 14 for x
y=-5/7(14)+20
y=-10+20
y=10
so x=14 and y=10 is another answer
lets try 21 for x
y=-5/7(21)+20
y=-15+20
y=5
so x=21 and y=5 is another answer
lets try 28 for x
y=-5/7(28)-20
y=-20+20
y=0
so x=28 and y=0 is an answer (if there can be only one of a species)
if we go further, then y will be negative so the answers are
(x,y)
(0,20)
(7,15)
(14,10)
(21,5)
(28,0)
if it is allowed that only one species exists then there are 5 possible answers
if both must exist simultaneously, then there are only 3 answers
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We know that the perimeter of a rectangle = 2(l + w)
l = length
w = width
In our problem,
l = 5x
w = 5x - 4
Let's create an inequality to help us solve this problem.
2(5x + (5x - 4)) ≥ 96
Let's start off by simplifying the terms inside the parentheses.
2(10x - 4) ≥ 96
Distribute the 2
20x - 8 ≥ 96
Add 8 to both sides.
20x ≥ 104
Divide both sides by 20
x ≥ 5.2
Let's plug 5.2 into x for our length and width.
Length = 5x = 5(5.2) = 26 cm
Width = 5x - 4 = 5(5.2) - 4 = 26 - 4 = 22 cm
The smallest possible dimensions for the rectangle are, length = 26 cm and width = 22 cm
