Let x = the first number
y = the second number
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First: set up the equations.
Four times a first number: 4x
Decreased by a second number: - y
Is 4: = 4
4x - y = 4.
The first number increased by: x +
three times the second number: 3y
is -25: = -25
x + 3y = -25.
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You can make your system of equations now.
4x - y = 4
x + 3y = -25
I would use substitution to solve these.
To do substitution, isolate a variable first, in one of the equations. I would probably isolate x in the second equation.
x + 3y = -25
x = -25 - 3y
Now, you can substitute -25 - 3y into 4x - y = 4, as x.
4x - y = 4
4(-25 - 3y) - y = 4
Now just solve for y.
-100 - 12y - y = 4
-13y = 104
y = -8
Now, you can put -8 as y into one of the original equations, I'll just use 4x - y = 4.
4x - y = 4
4x - (-8) = 4
4x + 8 = 4
4x = -4
x = -1
So the first number is -1, and the second -2.
a) If this trend continues, how many birds will be left by 2010 will be 525
b) The birds would there have been in 1990 will be 2475
<h3>What is rate of increase?</h3>
Rate of increase or decrease is defined as the increment or decrement in any quantity over a period of time constantly.
Here we have the data that:
There were 1500 birds in 2000 and they are decreasing at an annual rate of 6.5%.
a) If this trend continues, how many birds will be left by 2010
{1500x6.25}/{100}=97.5
So the bird decrement in the one year will be =97.5 so it will be in the 10 years or upto 2010 will be
97.5x10=975
So the birds left till 2010 will be:
Q=1500-975=525
b)The birds would there have been in 1990 will be:-
=1500+975=2475
Hence If this trend continues, how many birds will be left by 2010 will be 525.The birds would there have been in 1990 will be 2475
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Answer:
126
Step-by-step explanation:
A Nonagon has 9 sides. To answer this, the polygon has to be regular.
The Perimeter is 9*14 = 126
Answer:
Step-by-step explanation:
Our inequality is |125-u| ≤ 30. Let's separate this into two. Assuming that (125-u) is positive, we have 125-u ≤ 30, and if we assume that it's negative, we'd have -(125-u)≤30, or u-125≤30.
Therefore, we now have two inequalities to solve for:
125-u ≤ 30
u-125≤30
For the first one, we can subtract 125 and add u to both sides, resulting in
0 ≤ u-95, or 95≤u. Therefore, that is our first inequality.
The second one can be figured out by adding 125 to both sides, so u ≤ 155.
Remember that we took these two inequalities from an absolute value -- as a result, they BOTH must be true in order for the original inequality to be true. Therefore,
u ≥ 95
and
u ≤ 155
combine to be
95 ≤ u ≤ 155, or the 4th option
