Is that from khan academy?
Just askin
Answer:
Formula =

But there is no picture !!
In order to solve this problem, the approach should be formulating equations such that they form a system of linear equations. Let's start by assigning variables. Let x be the number of homeruns made by Peter, and y be the number of homeruns made by Alice. Therefore,
x = 2(y - 6)
This is the equation for the relationship between Peter's and Alice's hits. The second equation would be the sum of their hits:
x + y = 18
These are the two independent equations in order to solve the two unknowns, x and y. Substituting the first equation into the second equation,
2(y - 6) + y = 18
2y - 12 + y = 18
3y = 18 + 12
3y = 30
y = 10
Using y=10 to the first equation:
x = 2(10 - 6)
x = 8
Therefore, Peter made 8 homeruns, while Alice made 10 homeruns for a total of 18.
9514 1404 393
Answer:
a) -1 5/14
b) -1/3
c) -1 : 10
Step-by-step explanation:
a) 1/7 - 0,5·3 = 1/7 -3/2 = (1·2 -3·7)/(7·2) = -19/14 = -1 5/14
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b) (3/4 -0,25)·(-2/3) = (3/4 -1/4)·(-2/3) = (2/4)(-2/3) = (1/2)(-2/3) = (-1·2)/(2·3) = -1/3
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c) (1 5/6 -1,2) : (-6 1/3) = (11/6 -6/5) : (-19/3) = (11·5 -6·6)/(6·5) : (-190/30)
= (19/30) : (-190/30) = -19 : 190 = -1 : 10