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To solve the system of equations, we will apply the substitution method:
We start with the given equations:
(Equation 1)
(Equation 2)
Let's start by solving Equation 1 for :
Rearrange to isolate :
Multiply through by -1 to simplify:
(Equation 3)
Now, substitute Equation 3 into Equation 2:
Replace from Equation 3:
Multiply both sides of the equation by 7 to eliminate the fraction:
Expand and simplify:
Subtract 6 from both sides:
Divide by 43:
Substitute back into Equation 3 to solve for :
Therefore,
The solution to the system of equations is .
\( \begin{cases} x+y=8 \\ x-y=6 \end{cases} \)
These aren't proportions! We have addition and subtraction with reciprocal terms. Cross-multiplication only works when you have one fraction equals another fraction, not mixed operations.
Use substitution! Let , so your equations become and . Much easier to solve!
Look for the easier coefficient! In this problem, solving the first equation for gives us a clean expression to substitute into the second equation.
Check your work immediately! If , then is undefined. This means you made an error somewhere - go back and review your algebra.
Yes! Multiply the first equation by 2 and the second by 7, then add to eliminate the terms. Both methods work, but substitution is often clearer with reciprocal terms.
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