Find the two values of y which satisfy the simultaneous equation 3x + y = 8, x\(^2\) + xy = 6.
The correct answer is A. -1 and 5
Certainly, let's solve the simultaneous equations step by step:
Given equations:
1. \(3x + y = 8\)
2. \(x^2 + xy = 6\)
Let's solve the first equation for \(y\):
\[y = 8 - 3x\]
Substitute this expression for \(y\) into the second equation:
\[x^2 + x(8 - 3x) = 6\]
Simplify the equation:
\[x^2 + 8x - 3x^2 = 6\]
Combine the \(x^2\) terms and the \(x\) terms:
\[-2x^2 + 8x = 6\]
Divide both sides by -2:
\[x^2 - 4x = -3\]
Rearrange the equation:
\[x^2 - 4x + 3 = 0\]
Factor the quadratic equation:
\[(x - 3)(x - 1) = 0\]
This gives us two possible values for \(x\):
1. \(x - 3 = 0 \Rightarrow x = 3\)
2. \(x - 1 = 0 \Rightarrow x = 1\)
Now, substitute these values of \(x\) back into the equation \(y = 8 - 3x\) to find the corresponding values of \(y\):
For \(x = 3\): \(y = 8 - 3(3) = -1\)
For \(x = 1\): \(y = 8 - 3(1) = 5\)
Thus, the two pairs of values that satisfy the simultaneous equations are:
1. \(x = 3\) and \(y = -1\)
2. \(x = 1\) and \(y = 5\)
The correct answer is -1 and 5
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