Respuesta :

Answer:

a. t = 3 + √15  or  t = 3 - √15

b. t =  6.87  or  t = -0.87

Step-by-step explanation:

a.

Given : t² = 6t + 6

t² = 6t + 6 ⇔ t² - 6t + 6 = 0

USING THE QUADRATIC FORMULA:

[tex]t=\frac{6\pm \sqrt{\left( -6\right)^{2} -4\left( 1\right)(-6) } }{2}[/tex]

Then

[tex]t=\frac{6\pm \sqrt{36 +24 } }{2}[/tex]

Then

[tex]t=\frac{6\pm \sqrt{60 } }{2}[/tex]

Then

[tex]t=\frac{6\pm 2\sqrt{15 } }{2}[/tex]

Then

t = 3 ± √15

Then

t = 3 + √15  or  t = 3 - √15

…………………………………………………

b.

t = 3 + √15 = 6.872983346207 ≈ 6.87

or  t = 3 - √15 = -0.872983346207 ≈ -0.87