Question

Докажите тождество
(7x-7)×0,6-0,8×(4x-5)-(-1,7-1,4x)=10,3
40баллов пожалуйста скорее​

Answer 1

$( 7X - 7 ) * 0.6 = 4.2X - 4.2$

$-0.8 * ( 4X - 5 ) = -3.2X + 4$

$- ( -1.7 - 1.4X ) = 1.7 + 1.4X$

$4.2X - 4.2 - 3.2X + 4 + 1.7 + 1.4X = 10.3$

$4.2X - 3.2X + 1.4X = X + 1.4X = 2.4X$

$-4.2 + 4 + 1.7 = 1.5$

$2.4X + 1.5 = 10.3$

$2.4X = 10.3 - 1.5$

$2.4X = 8.8$

$X = 2$