To solve for t, factor the left side of t2−4=0, giving (t−2)(t+2)=0. Therefore, either t−2=0 or t+2=0. If t−2=0, then t=2, and if t+2=0, then t=−2. Since it is given that t>0, the value of t must be 2. Another way to solve for t is to add 4 to both sides of t2−4=0, giving t2=4 . Then, taking the square root of the left and the right side of the equation gives t=±√4=±2. Since it is given that t>0, the value of t must be 2.