Question

Solve for x: -2x(x-3)=-11 (correct two decimal place)

Answer 1

-2x(x-3) = -11

-2x(x) -2x(-3) = -11
-2x² + 6x = - 11
-2x² + 6x + 11 = 0

Let us use the quadratic formula in solving for the value of x.

-2x² + 6x + 11 = 0

a = -2 ; b = 6 ; c = 11

x = (-b + √b² -4ac) ÷ 2a

x = (-6 + √6² - 4(-2)(11)) ÷ 2(-2)
x = (-6 + √36 + 88) ÷ -4
x = (-6 + √124) ÷ -4
x = (-6 + 11.14) ÷ -4
x = 5.14 ÷ -4
x = -1.285 or -1.29

x = (-6 - 11.14) ÷ -4
x = -17.14 ÷ -4
x = 4.285 or 4.29