1) t²-5t+4=0
t= 4
t= 1
x²= 4
x²= 1
x=2, x=-2
x=1, x=-1
2) t²-8t-9=0
t= 9
t= -1
x²= 3
x²= ø
x= 3, x= -3
3) t²-7t+10=0
t= 5
t= 2
2x²+3= 5
2x²+3= 2
x= -1
x= 1
x= ø
