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I. x^(2) + 4x = 21 II y^(2) - 6y + 8 ...

I.` x^(2) + 4x = 21`
II` y^(2) - 6y + 8 = 0`

A

` x gt y`

B

`y gt x`

C

` x ge y`

D

x = y or a relationship between x and y cannot be established.

Text Solution

AI Generated Solution

The correct Answer is:
Let's solve the equations step by step. ### Step 1: Solve for x in the equation \( x^2 + 4x = 21 \) First, we need to rearrange the equation to set it to zero: \[ x^2 + 4x - 21 = 0 \] ### Step 2: Factor the quadratic equation Now we will factor the quadratic equation. We need to find two numbers that multiply to \(-21\) (the constant term) and add to \(4\) (the coefficient of \(x\)). The numbers \(7\) and \(-3\) satisfy this condition: \[ x^2 + 7x - 3x - 21 = 0 \] ### Step 3: Group the terms Next, we group the terms: \[ (x^2 + 7x) + (-3x - 21) = 0 \] ### Step 4: Factor by grouping Now, we factor out the common terms: \[ x(x + 7) - 3(x + 7) = 0 \] This can be simplified to: \[ (x - 3)(x + 7) = 0 \] ### Step 5: Solve for x Setting each factor to zero gives us the possible values for \(x\): \[ x - 3 = 0 \quad \Rightarrow \quad x = 3 \] \[ x + 7 = 0 \quad \Rightarrow \quad x = -7 \] So, the solutions for \(x\) are: \[ x = 3 \quad \text{or} \quad x = -7 \] ### Step 6: Solve for y in the equation \( y^2 - 6y + 8 = 0 \) Now we will solve the second equation. We can factor this as well. We need two numbers that multiply to \(8\) and add to \(-6\). The numbers \(2\) and \(4\) fit this requirement: \[ y^2 - 4y - 2y + 8 = 0 \] ### Step 7: Group the terms We group the terms: \[ (y^2 - 4y) + (-2y + 8) = 0 \] ### Step 8: Factor by grouping Factoring gives us: \[ y(y - 4) - 2(y - 4) = 0 \] This simplifies to: \[ (y - 2)(y - 4) = 0 \] ### Step 9: Solve for y Setting each factor to zero gives us the possible values for \(y\): \[ y - 2 = 0 \quad \Rightarrow \quad y = 2 \] \[ y - 4 = 0 \quad \Rightarrow \quad y = 4 \] So, the solutions for \(y\) are: \[ y = 2 \quad \text{or} \quad y = 4 \] ### Step 10: Analyze the relationship between x and y Now we have the values: - \(x = 3\) or \(x = -7\) - \(y = 2\) or \(y = 4\) We need to analyze the relationship between \(x\) and \(y\): - For \(x = 3\): \(y = 2\) (3 > 2) and \(y = 4\) (3 < 4) - For \(x = -7\): \(y = 2\) (-7 < 2) and \(y = 4\) (-7 < 4) From this analysis, we can conclude that: - \(x\) can be greater than \(y\) in one case (when \(x = 3\) and \(y = 2\)). - \(x\) can be less than \(y\) in other cases (when \(x = -7\) and both values of \(y\)). - There is no consistent relationship between \(x\) and \(y\). Thus, we cannot establish a definitive relationship between \(x\) and \(y\).

Let's solve the equations step by step. ### Step 1: Solve for x in the equation \( x^2 + 4x = 21 \) First, we need to rearrange the equation to set it to zero: \[ x^2 + 4x - 21 = 0 ...
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