Question

срочно даю 100 баллов,
7 класс ,2 задания

Answer 1

Объяснение:

0,6(4х-12)-0,4(5х-7)=2,4х-7,2-2х+2,8=0,4х-4,4

при х=4 1/6=25/6

0,4 * 25/6 - 4,4 = 10/6 - 44/10 = (50-132)/30 = -82/30 =-2 11/15

5 1/7 * (у-7) - 3 3/7 * (14-у) = 36/7 * (у-7) - 24/7 * (14-у)=

=(36у+252)/7 - (336-24у)/7 = (36у-252-336+24у)/7 = (60у-588)/7

при у--0,4

(60*(-0,4)-588)/7 = (-24-588)/7 = -612/7 = -87 3/7

Answer 2

Ответ:

Объяснение:

1)  0.6(4x-12)-0.4(5x-7) = 2.4x-7.2 - 2x+2.8 = 0.4x - 4.4 =>

при x=4 1/6 =>

0.4*4 1/6 - 4.4 = 4/10*25/6 - 4.4 = 5/3 - 4 4/10 = 1 2/3 - 4 2/5 =

=> НОК(3;5)=15 => 1 10/15 - 4 6/15 = -(4 6/15 - 1 10/15) = -3 (6-10)/15 =

= -2 (15+6-10)/15 = -2 11/15.

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2)  5 1/7(y-7) - 3 3/7(14-y) = 36/7y - 36 - 48+24/7y =60/7y-84=8 4/7y-84=>

при y=-0,4=>

8 4/7*(-0.4)-84 = -60/7 *2/5 - 84 = -120/35 - 84 = -24/7 - 84=

= -3 3/7-84= -87 3/7.