- 0,6( 1,6b - 5 ) - ( 2,9b - 8 ) - 4( 4 - 1,5b ) = - 0,96b + 3 - 2,9b + 8 - 16 + 6b = 6b - 3,86b + 11 - 16 = 2,14b - 5
b = - 9/13
2,14 • ( - 9/13 ) - 5 = - ( 107/50 )•( 9/13 ) - 5 = - ( 963/650 ) - 5 = - 1 313/650 - 5 = - 6 313/650 br />
-0,6(1.6b - 5) - (2.9b - 8) - 4(4 - 1.5b) =
= - 0.6 * 1.6b - 0.6 * (-5) - 2.9b + 8 - 4*4 - 4* (-1.5b) =
= -0.96b + 3.0 - 2.9b +8 -16 +6b =
= (-0.96b -2.9b +6b) + (3+8-16) =
= (6.00b - 3.86b) + (11-16) =
= 2.14b - 5
при b= - 9/13
2.14 * (-9/13) - 5 = 214/100 * (-9/13) - 5 = 107/50 * (-9/13) -5 =
= - 963/650 - 5 = - (1 313/650 + 5 ) = - 6 313/650