The reason why we used plus or minus when taking the square root is because; The square root of terms separated by addition and subtraction cannot be calculated individually.
<h3>How to use the quadratic formula?</h3>
The general formula for a quadratic equation is;
ax² + bx + c = 0
Now, the steps to derive quadratic formula to find the roots of this equation are as follows;
Step 1; Divide both sides of the equation by a to get;
x² + (b/a)x + c/a = 0
Step 2; Transpose the quantity c/a to the right side of the equation to get; x² + (b/a)x = -c/a
Step 3; Complete the square by adding b²/4a² to both sides of the equation to get; x² + (b/a)x + b²/4a² = -c/a + b²/4a²
Step 4; Factor the left side and combine the right side to get;
(x + (b/2a))² = (b² - 4ac)/(4a²)
Step 5: Extract the square-root of both sides of the equation to get;
x + (b/2a) = ±(√(b² - 4ac))/2a
The reason why we used plus or minus when taking the square root is because The square root of terms separated by addition and subtraction cannot be calculated individually.
Read more about Quadratic Formula at; brainly.com/question/8649555
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Start by subtracting 2. You end up with -5x=20. Because the five is negative, the second number must be negative, because two negatives always make a positive in multiplication. Pick the only negative answer, which is D, -4
Answer:
3n²+3n-60
Step-by-step explanation:
Area of rectangle= L*W
A=3(n-1)(n+2)
A=3(n²+n-2)
A=3n²+3n-6
54=3n²+3n-6
3n²+3n-6-54=0
3n²+3n-60=0
