29*(145-6Х)=203
145-6Х=203:29
145-6Х=7
6Х=145-7
6Х=138
Х=138:6
Х=23
Проверка
29*(145-6*23)=203
1)23*6=138
2)145-138=7
3)29*7=203
<span>
ВD=</span>√CD^2+BC^2=√6*6+8*8=√<span>100</span>=10(cм)
С1D=√CC1^2+CD^2=√12*12+6*6=√180~13,42(см)
С1В=√ВС^2++CC1^2=√8*8+12*12=√208~ 14,42(см)<span><span>
p = (</span><span><span>a + b + c):</span>2</span> = <span>1/2</span>(10 + 14.42 + 13.42) = 18.92(см)</span>
S = √<span>p(p - a)(p - b)(p - c)</span><span> = </span>
= √(18.92)(18.92 - 10)(18.92 - 14.42)(18.92 - 13.42)<span> =</span>
<span><span> = √(18.92)·(8.92)·(4.5)·(5.5) = </span><span>√4176.9684</span> =64,63(кв.см)</span>
104*у-12 =1132
104у = 1132+12
104y = 1144
у = 1144 : 104
у = 11
29*(145-6*х) = 203
(29*145) - (29*6х) =203
4205-174х=203
174х=4205-203
174х=4002
х=4002:174
х=23
340:30=11 (ост.10)
Надеюсь верно