How do you solve the equation 4+sqrt(4t-4)=t?

1 Answer
Oct 17, 2016

t=2 or t=10

Explanation:

4+ sqrt(4t-4)= t

Subtract 4 from both sides.

sqrt(4t-4)= t-4

Square both sides.

4t-4 = (t-4)^2

Expand the right side.

4t-4= (t-4)(t-4)

4t-4= t(t-4)-4(t-4)

4t-4=t^2-4t-4t+16 (since multiplying two negatives produces a positive)

Simplify the equation on the right.

4t-4=t^2-8t+16

Subtract (4t-4) from both sides.

0=t^2-12t+20 or t^2 -12t+20=0

Factorise the equation.

t^2-2t-10t+20=0

t(t-2)-10(t-2)=0

(t-2)(t-10)=0

:. t=2 or t=10