Question

Розвяжітьь будьласка 7 і 8 ето срочнно

Answer 1

Ответ:

Пошаговое объяснение:

7) 0.7(6y-5)=0.4(y-3)-1.16

4.2y-3.5=0.4y-1.2-1.16

4.2y-0.4y=-1.2-1.16+3.5

3.8y=1.14

y=0.3

8) (5.4*(-3$\frac{1}{3}$)+13.8): 1 $\frac{13}{15}$ + 3 $\frac{5}{6}$ = 1$\frac{7}{12}$

1) 5.4*(-3$\frac{1}{3}$) = - ( 5$\frac{4}{10}$ * $\frac{10}{3}$)=- (5 $\frac{2}{5}$  * $\frac{10}{3}$) = - ( $\frac{27}{5}$ * $\frac{10}{3}$) = - ( $\frac{3*9*2*5}{5*3}$)= -18

2) -18+13.8=-4.2

3) -4.2: 1 $\frac{13}{15}$ = -4 $\frac{2}{10}$ : $\frac{28}{15}$ = - 4$\frac{1}{5}$ :  $\frac{28}{15}$ = - $\frac{21}{5}$ * $\frac{15}{28}$ = - $\frac{3*7*3*5}{5*4*7}$ = - $\frac{9}{4}$

4) - $\frac{9}{4}$ + 3 $\frac{5}{6}$ = - $\frac{9}{4}$ + $\frac{23}{6}$ = $\frac{-9*3+23*2}{12}$=$\frac{-27+46}{12}$= $\frac{19}{12}$ =1 $\frac{7}{12}$