請教數學jj題

25. (1,2) is on the y=ax^2+bx+c, is (-1,2) also on it?

A. f(a)=f(-a) for all f(x)=ax^2+bx+c

B. b=0

26. k@ = k+1 if k is odd, k-1 if k is even. Is (a@)^2x(b@) even?

A. a is even

B. b is odd

27.要求 5X-3Y=?
A.(x/0.3)-(Y/0.5)=0.1
B.(x/0.5)-(Y/0.3)=0.1