Using substitution to solve the system below, what expression should be substituted into the first equation? 2x-4y=-4 and x+2y=8
2 answers:
Answer:
Given the system of equation:
......[1]
......[2]
we can rewrite equation [2] as;
......[3]
Substitute equation [3] into [1] to eliminate x, and solve for y;
Using distributive property:
Combine like terms;
16 - 8y = -4
Add 4 to both sides we have;
20 - 8y = 0
Add 8y to both sides we have;
20 = 8y
Divide 8 to both sides we have;
Substitute the y-value in [3] we have;
x = 8 - 5 = 3
Therefore, the expression should be substituted into the first equation is, and also the value of x = 3 and y = 2.5
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Part A:
Let the length of one of the sides of the rectangle be L, then the length of the other side is obtained as follow.
Let the length of the other side be x, then
Thus, if the length of one of the side is x, the length of the other side is 8 - L.
Hence, the area of the rectangle in terms of L is given by
Part B:
To find the domain of A
Recall that the domain of a function is the set of values which can be assumed by the independent variable. In this case, the domain is the set of values that L can take.
Notice that the length of a side of a rectangle cannot be negative or 0, thus L cannot be 8 as 8 - 8 = 0 or any number greater than 8.
Hence the domain of the area are the set of values between 0 and 8 not inclusive.
Therefore,
Let the length of one of the sides of the rectangle be L, then the length of the other side is obtained as follow.
Let the length of the other side be x, then
Thus, if the length of one of the side is x, the length of the other side is 8 - L.
Hence, the area of the rectangle in terms of L is given by
Part B:
To find the domain of A
Recall that the domain of a function is the set of values which can be assumed by the independent variable. In this case, the domain is the set of values that L can take.
Notice that the length of a side of a rectangle cannot be negative or 0, thus L cannot be 8 as 8 - 8 = 0 or any number greater than 8.
Hence the domain of the area are the set of values between 0 and 8 not inclusive.
Therefore,
<h3>Two answers: 5, 7</h3>
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Explanation:
A drawing may be helpful to see what's going on. Check out the diagram below. This is one way of drawing out the two triangles. The locations of the points don't really matter, and neither does the the orientation of how you rotate things. What does matter is we have the right points connected to form the segments mentioned.
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For now, focus on triangle TIP only. In order to have this be isosceles, we must make TP = 5 or TP = 7.
If TP = 5, then it's the same length as TI.
If TP = 7, then it's the same length as PI.
In either case, we have exactly two sides the same length (the other side different) which is what it means for a triangle to be isosceles.
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Let's consider triangle TOP. For it to be isosceles, we must have two sides the same length. We already locked in TP to be either 5 or 7 in the previous section above. So there's no way that TP could be 11 units long to match up with PO = 11.
If TP = 5, then OT must also be 5 units long so that triangle TOP is isosceles.
If TP = 7, then OT = 7 for similar reasoning.
Either way, TP only has two choices on what it could be.
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In short, we basically just write the first two values given to us to get the two triangles to be isosceles. We can't use TP = 11 as it would make triangle TIP to be scalene (all sides are different lengths).