1) 8*400=3 200(м) - по 8 кругов
2) 3 200/200=16(мин) - t (время)
Ответ : t = 16 мин
1)<span>9*7=63</span>
<span>2)36+6=42</span>
<span>3)49/7=7</span>
<span>4)7*5=35 тоесть 7х=35; х=35/7; х=5</span>
<span>5)54/6=9</span>
<span>5)63/7=9</span>
<span>6)13-7=6</span>
S = 1/2 *sinA* b* c
S = 20
sin A = sin 30 = 1/2
b = 10
c = ?
20 = 1/4*10c
20 = 2.5C
c = 8
862-x=284
х= 862-284
х=578
х*320=960
х=960/320
х=3