4,6 * (- 2,5) = - 4,6 * 2,5 = - 11,5
- 25, 344 : (- 3,6) = 253,44 : 36 = 7,04
- 1 1/7 * 1 5/6 = - 8/7 * 11/6 = - 88/42 = - 44/21 = - 2 2/21
1 1/8 : (- 3 3/8) = - 9/8 : 27/8 = - 9/8 * 8/27 = - 1/3
- 0,77 * 4/9 - 4/9 * 2,83 = - 4/9 * ( 0,77 + 2,83) =
= - 4/9 * 3,6 = - 4/9 * 36/10 = 16/10 = 1,6
X^4-x²y²+y^4=(x²+y²)²-2x²y²-x²y²=(x²+y²)²-3x²y² =(х²+у²)²-3(ху)²
Если
x²+y²=8
xy=3,то
=8²-3*3²=64-27=37