How do you solve x( x - 5) = 66x(x−5)=66?

3 Answers
Bill Jorgensen
May 19, 2018

x = 11 and -6x=11and−6

Explanation:

x(x-5) = 66x(x−5)=66

x^2-5x-66 =0x2−5x−66=0

(x+6)(x-11) = 0(x+6)(x−11)=0

x+6 =0x+6=0

x = -6x=−6

and

x - 11 =0x−11=0

x = 11x=11

so: x = 11 and -6x=11and−6

Nallasivam V
May 19, 2018

x=11x=11
x=-6x=−6

Explanation:

Given -

x(x-5)=66x(x−5)=66

x^2-5x=66x2−5x=66

x^2-5x+25/4=66+25/4=(264+25)/4=289/4 x2−5x+254=66+254=264+254=2894

(x-5/2)^2=289/4(x−52)2=2894

x-5/2=+-sqrt((289)/4)=17/2x−52=±√2894=172

x=17/2+5/2=22/2=11x=172+52=222=11

x=11x=11

x=-17/2+5/2=-12/2=-6x=−172+52=−122=−6

x=-6x=−6

Meave60
May 19, 2018

x=-6,11x=−6,11

Explanation:

Solve:

x(x-5)=66x(x−5)=66

Expand the left-hand side.

x^2-5x=66x2−5x=66

Move all terms to the left-hand side.

x^2-5x-66=0x2−5x−66=0

Factor the left-hand side.

Find two numbers that when added equal -5−5 and when multiplied equal -66−66. The numbers 66 and -11−11 meet the requirements.

(x+6)(x-11)=0(x+6)(x−11)=0

Solutions for xx.

x+6=0x+6=0

x=-6x=−6

x-11=0x−11=0

x=11x=11

x=-6,11x=−6,11

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