-16t^2+400=0
16t^2=400
take square root on both sides.
4t=20
t=20/4
t=5
X= 0 and 1 are the answers
17. 2x<16 x=7 or lower
All I can help you with is #17,
sorry that I can't answer the other 3.
I hope this helped! :-)
Okay so a couple of things to know to best solve this problem
1) all angles in a triangle add to 180
2) a straight line the angles above it equal 180 and the angles below it add to 180
3) vertical angles are equal (vertical angles are angles that make an X the opposite angles are called vertical angles)
