An.swer:
171.68
Step-by-step explanation:
Answer:
you only put a parenthesis around a number if it is negative
Step-by-step explanation:
Let the number of adults be x, then number of male students is 1 + 7x and the number of female students is (1 + 7x)/2.
x + 1 + 7x + (1 + 7x)/2 = 82
2x + 2 + 14x + 1 + 7x = 164
23x = 164 - 2 - 1 = 161
x = 161/23 = 7
Therefore, number of male students is 1 + 7(7) = 1 + 49 = 50
and the number of female students is 50/2 = 25.
Solving a system of equations we can see that:
They need to use 80kg of the 60% chocolate and 20kg of the 40% chocolate.
<h3>
How to find how much of each candy needs to be used?</h3>
Let's define the variables:
- x = kilograms of the 40% chocolate.
- y = kilograms of the 60% chocolate.
They want to make 100kg, then:
x + y = 100
And the concentration must be of the 56%, then we can write:
x*0.4 + y*0.6 = (100)*0.56 = 56
Then we have a system of equations:
x + y = 100
x*0.4 + y*0.6 = 56
To solve this, we can isolate x on the first equation to get:
x = 100 - y
Now replace that in the other equation:
(100 - y)*0.4 + y*0.6 = 56
40 + y*0.2 = 56
y*0.2 = 16
y = 16/0.2 = 80
This means that they need to use 80kg of the 60% chocolate and the other 20kg of the 40% chocolate.
If you want to learn more about systems of equations:
brainly.com/question/13729904
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