1)
3 * 4⁻² + 2³ =
= 3/4² + 8 =
= 3/16 + 8 = 8 3/16,
2)
0,4⁰ - (0,25)³ =
= 1 - (1/4)³ =
= 1 - 1/64 =
= 64/64 - 1/64 = 63/64
(m-n)²= m²-2mn+n²=5
9-2mn=5
4=2mn
mn=2