1) To find the value of t in the equation X1 = 10t and X2 = 300-20t, we can set the two expressions equal to each other:

10t = 300-20t

Add 20t to both sides:
30t = 300

Divide both sides by 30:
t = 10

Therefore, the value of t is 10 in this equation.

2) To find the value of t in the equation X1 = 2-t and X2 = 1+t, we can set the two expressions equal to each other:

2-t = 1+t

Add t to both sides:
2 = 1+2t

Subtract 1 from both sides:
1 = 2t

Divide both sides by 2:
t = 0.5

Therefore, the value of t is 0.5 in this equation.