Respuesta :
Answer:
140
Step-by-step explanation:
Suppose,
x drinks were sold for 2$
y drinks were sold for 5$
therefore, x+y = 250....( 1 )
and 2x+5y = 830......( 2 )
multiply equation ( 1 ) with 2,
2x+2y = 500......( 3 )
Subtract equation ( 3) from (2)
3y = 330
or, y = 110
so, x = 140
so, 140 drinks were sold for 2$
140 drinks were sold for $2.
What are variables and how to define them?
A variable is any letter or symbol that represents a number with an unknown value.
We can define them simply by any alphabet like x or y.
What are linear equations and how to make them?
A linear equation is generally of the form Ax + By = C, where the two variables are x and y, while A, B and C are constants.
A constant is a value or number that never changes and it's constantly the same.
We have to choose our variables and put them in the equation such that it holds properly and satisfies all the conditions for the given question.
How to solve linear equations?
There are several methods of solving linear equations. we may have the linear equation with two or three or many variables. The methods are:
- substitution method,
- elimination method,
- graphing method.
In the given question first, let's make our variables.
Let, the number of drinks was sold for 2$ is x, and the number of drinks was sold for 5$ is y.
And now we will try to make the linear equation with two variables because we have two variables satisfying the conditions in the question given.
One thing to remember carefully is that we have to have two equations if we have two variables.
The restaurant sold a total of 250 drinks so we can write,
x + y = 250
The total sales of drinks for the night was $830 so again we can write,
2x + 5y = 830
Now, we have made the two equations, so we will solve them with help of the substitution method.
Let's, take the equation and just find the value of x,
x + y = 250
x = 250 - y
Now, we will substitute the value of x in the other equation,
2×(250 - y) +5y = 830
Multiplying 2 with the term (250 - y),
500 - 2y + 5y = 830
Now, solve for y,
500 +3y = 830
subtracting 500 both sides we get,
500 - 500 + 3y = 830 - 500
3y = 330
Dividing both sides by 3 we get,
(3y) / 3 = 330 / 3
y = 110
Now, again putting the value of y in the equation x + y = 250 we get,
x + 110 = 250
Subtracting 110 both sides we get,
x + 110 - 110 = 250- 110
x = 140
Now, we can conclude that the number of drinks sold for 2$ is 140 and the number of drinks sold for 5$ is 110.
Therefore, 140 drinks were sold for $2.
To know more about linear equations, making them and solving them click here - brainly.com/question/384631
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