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Explanation:</h2><h2>
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Here we need to set a system of two linear equations in two variables. So:
- <em>The sum of digits in a two digit number formed by two digits from 1 to 9 is 8:</em>
Let
be those digits, then:

- <em>If 9 is added to a number then both the digits become equal. find the number:</em>
<em />
<em />
<em />
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But from eq 1:

Substituting y into the expression 1:

The x-value will be found by hit and trial, so:

We have to reject this solution because digits are different.

We have to reject this solution because digits are different.

<em>Then this is a two digit number formed by two equal digits. </em>
Finally, the number is:
44
Answer:
45 students are in the Environmental Club
Step-by-step explanation:
25/100 = x/180 (cross multiply)
(180 * 25) / 100 = 45
Answer:
Emma will pay $5.25
Step-by-step explanation:
In order to find this, we first need to find the amount of the discount. We can do that by taking the overall amount and multiplying it by the percentage decrease.
$7.50 * 30% = $2.25
Now since we know the size of the discount, we can subtract it from the original cost.
$7.50 - $2.25 = $5.25