If x - 2y + z = 5 and -x + 3y - z = 2, then y = ?
1 answer:
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Answer:
x = -1
Step-by-step explanation:
The usual approach to these is to square the radicals until they are gone.
Each time the equation is squared, the possibility of an extraneous root is introduced. Here, x=3 is extraneous: it does not satisfy the original equation.
The solution is x = -1.
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Using a graphing calculator to solve the original equation can avoid extraneous solutions. The attachment shows only the solution x = -1. Rather than use f(x) = 2, we have rewritten the equation to f(x)-2 = 0. The graphing calculator is really good at showing the function values at the x-intercepts.
