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System of Equations

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Solve the system of equations:
3x + y = -7
x - y = -5

Solve the system of equations:
3x + 2y = 18
y = 3x

Which of the following is true of a base period for an index number?

The numerator spears
It appears in the denominator
It must have occurred after the year 1980
It cannot be less than 100

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Solution Preview

Solve the system of equations:
3x + y = -7
x - y = -5

METHOD: Solve the second equation for x, then plug that into the first equation. Simplify to solve for y, then solve for x.

Solve second equation for x:
x - y = -5
x = y - 5

Plug result into first equation:
3x + y = -7
3(y - 5) + y = -7
3y - 15 + y = -7
4y - 15 = -7
4y = 8
y = 2

Use ...

Solution Summary

This solution explains how to solve the given system of equations and how to solve a question involving the base period of an index number.

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dx/dt = 4x - y
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