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The sum of two numbers is at least 8, and the sum of one of the numbers and 3 times the second mumber isno more than 15.

The sum of two numbers is at least 8, and the sum of one of the numbers and 3 times-example-1
User Tashuhka
by
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1 Answer

18 votes
18 votes

As given by the question

There are given that the sum of the two numbers is at least 8.

Now,

Let the unknown numbers be x and y

Then,

If the sum of the two numbers is at least 8 then:


x+y\ge8

Similarly, the sum of one of the numbers and 3 times the second number is no more than 15

Then,


x+3y\leq15

Now,

From the both of the inequality:


\begin{gathered} x+y\ge8 \\ x+3y\leq15 \end{gathered}

Then, find the first and second nuber:

So,


\begin{gathered} x+y\ge8 \\ x\ge8-y\ldots(a) \end{gathered}

Then, Put the value of x into the second equation

Then,


\begin{gathered} x+3y\leq15 \\ 8-y+3y\leq15 \\ 8+2y\leq15 \\ 2y\leq15-8 \\ y\leq(7)/(2) \\ y\leq3.5 \end{gathered}

Then,

Put the value of y into the equation (a)


\begin{gathered} x\ge8-y \\ x\ge8-3.5 \\ x\ge4.5 \end{gathered}

Hence, the first number and second number is shown in below:


\begin{gathered} x\ge4.5 \\ y\leq3.5 \end{gathered}

The graph of the given result is shown below:

The sum of two numbers is at least 8, and the sum of one of the numbers and 3 times-example-1
User Elben Shira
by
2.7k points
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