Which equation in the standard form ax^2+bx+c=0 is obtained when (x+3)^2 = 25 is written in standard form?
Answer and explanation
Correct answer: x^2+6x-16=0
Expand the perfect square: \((x+3)^2 = x^2+6x+9\). Subtract 25 from both sides: \(9-25=-16\), giving \(x^2+6x-16=0\). Thus option A is correct. Option B has the wrong sign on the constant (+16 instead of -16). Options C and D have incorrect coefficients for x or the constant term. Exam tip: always expand the square first, move all terms to one side and then combine like terms to reach the standard form.
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What is the correct answer to this question?
x^2+6x-16=0
Why is this the correct answer?
Expand the perfect square: \((x+3)^2 = x^2+6x+9\). Subtract 25 from both sides: \(9-25=-16\), giving \(x^2+6x-16=0\). Thus option A is correct. Option B has the wrong sign on the constant (+16 instead of -16). Options C and D have incorrect coefficients for x or the constant term. Exam tip: always expand the square first, move all terms to one side and then combine like terms to reach the standard form.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Introduction to Quadratic Equations.
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