166k views
10 votes
Solve for x.
2x² +21x-61 = (x+7)²

Please

User Zuguang Gu
by
7.8k points

2 Answers

10 votes
after you rewrite the equation, identify the coefficients , substitute the coefficients and simplify the expression you’ll be left with 489
User Sachin Tyagi
by
8.2k points
4 votes

Answer:


x = (-7 +√(489) )/(2)


x = (-7 - √(489) )/(2)

Explanation:

2x² +21x-61 = (x+7)²

expand

2x² + 21x - 61 = x² + 14x +49

move everything to one side

x² + 7x - 12 = 0

use quadratic formula


x = \frac{-b +- \sqrt{b^(2)-4ac } }{2a}

plug in the values


x = \frac{-7 +- \sqrt{7^(2)-4(1)(-110) } }{2(1)}

solve


x = (-7 +- √(49-4(1)(-110) ) )/(2)


x = (-7 +- √(49 + 440 ) )/(2)


x = (-7 +- √(489) )/(2)

User Biplob Biswas
by
8.4k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories