<span>
(670+31)•407=285307
(258+902)•407=472120
5096:(706-69)=8
6370:(706-615)=70
</span><span>
(1) (670+31)*407=285307
(2) (258+902)*407=472120
(3) 5096/(706-69)=8
<span>(4) 6370/(706-615)=70</span></span>
А)х\24=3\28.28х = 72х = 72/28 = 18/7б)х:13=24:39. х/13 = 8/13х = 8
-4,8+(-0,72)+(-5,2)+(-9,3)
-4.8-0.72-5.2-9.3
-20.02
Ответ:-20.02