(у+9)(у-2)+(3-у)(6+5у)
у=-1/2
(-1/2+9)((-1/2)-2)+(3-(-1/2)(6+5(-1/2)= -9
Пошаговое объяснение:
- 1/ 2 + 9 = 9 - 1 /2 = 9·2 2 - 1 /2 = 18 /2 - 1/ 2 = 18 - 1/ 2 = 17/ 2 = 8·2 + 1 /2 = 8 1 /2 = 8.5
- 1 /2 - 2 = -2 1 /2 = -2.5
3 - (- 1 /2 ) = 3 + 1/ 2 = 3 + 1/ 2 = 3 1/ 2 = 3.5
5×(- 1 /2 ) = -5× 1/ 2 = - 5·1 /2 = - 5 /2 = - 2·2 + 1 /2 = -2 1 /2 = -2.5
8 1 2 ×(-2 1 /2 ) = -8 1 /2 ×2 1/2 = - 1 + 8·2 /2 × 1 + 2·2 /2 = - 17 2 × 5 /2 = - 17·5/ 2·2 = - 85 /4 = - 21·4 + 1 /4 = -21 1 /4 = -21.25
6 + (-2/ 1 2 ) = 6 - 2 / 1 2 = 6 - 2 - 1 /2 = 4 - 1 2 = 4·2 2 - 1 2 = 8 2 - 1 2 = 8 - 1 2 = 7 2 = 3·2 + 1 2 = 3 / 1 2 = 3.5
3 1 2 ×3 1 2 = 1 + 3·2 2 × 1 + 3·2 2 = 7 2 × 7 2 = 7·7 2·2 = 49 4 = 12·4 + 1 4 = 12 1 4 = 12.25
-21 1 4 + 12 1 4 = 12 1 4 - 21 1 4 = 1 + 12·4 4 - 1 + 21·4 4 = 49 4 - 85 4 = 49 - 85 4 = - 36 4 = - 9 · 4 4 = - 9 = -9
при у=0 х=(8+0):4=8:4=2 (2;0)
4) х+3у=-2 х=-3у-2 при у=0 х=-3*0-2=0-2=-2 (-2;0)
при у=3 х=-3*3-2=-9-2=-11 (-11;3)
5) 5х+у=10 5х=10-у х=(10-у):5 при у=5 х=(10-5):5=1 (1;5)
при х=4 х=(10-4):5=6:5=1,2 (1,2; 4)
6) -х+8у=-3 -х=-3-8у х=3+8у при у=1 х=8*1+3=11 (11;1)
при у=-2 х=3+8*(-2)=3-16=-13