Can u guys help me plz
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Answer:
It takes 1 seconds for push-ups and 3 seconds for sit-ups for Mei to do exercise.
Step-by-step explanation:
Given:
Let the time taken for push-ups be 'x'.
Let the time taken for sit-ups be 'y'.
Now Given:
17 push-ups and 6 sit-ups, it takes a total of 35 seconds.
So we can say that;
Also Given:
41 seconds to do 20 push-ups and 7 sit-ups.
so we can say that;
Now Multiplying equation 1 by 7 we get;
Now Multiplying equation 2 by 6 we get;
Now Subtracting equation 3 from equation 4 we get;
Now substituting the value of x in equation 1 we get;
Hence It takes 1 seconds for push-ups and 3 seconds for sit-ups for Mei to do exercise.
<h3>Answers:</h3>
- f(-5) = 23
- f(12) = 433
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Explanation:
The given piecewise function is
At first piecewise functions may be strange confusing things, but they aren't so bad. I like to think of it like this: f(x) is a function that changes its identity based on what the input x is. We have three situations
- f(x) = -4x+3 when x < 3
- f(x) = -x^3 when
- f(x) = 3x^2+1 when x > 8
In a sense, we have three different functions but they are combined somehow.
If x is smaller than 3, then we go for the first definition. Or if x is between 3 and 8, then we go for the second definition. Or if x is larger than 8, then we go for the third definition.
-----------------------
f(-5) means f(x) when x = -5. We see that -5 is smaller than 3, so x = -5 makes x < 3 true. We'll use the first definition
f(x) = -4x+3
f(-5) = -4(-5)+3
f(-5) = 20+3
f(-5) = 23
------------------------
Now the input is x = 12. This is larger than 8. In other words, x = 12 makes x > 8 true. We'll use the third definition
f(x) = 3x^2+1
f(12) = 3(12)^2+1
f(12) = 3(144)+1
f(12) = 432+1
f(12) = 433
------------------------
Side notes:
- We won't use the second definition since we don't have any x inputs between 3 and 8
- To say "less than or equal to" on a keyboard, you can write "<=" without quotes. For example,
is the same as x<=5