<span>х(х+10)=119
</span><span>х²+10х-119=0
</span>D = b² - 4ac = 10² - 4·1·(-119) = 100 + 476 = 576
x₁<span><span> =(</span><span><span>− 10 + √576)/</span>2 · 1</span>=(<span>− 10 + 24)/2</span>=<span>14/2</span>=<span>7
</span></span>x₂<span><span> =(</span><span><span>− 10 − √576)/</span>2 · 1</span>=(<span>− 10 − 24)2</span>=<span>− 34/2</span>=−<span>17
</span></span>х*(х-18)=115
<span>х²-18х-115=0
</span>D = b² − 4ac = (− 18)²<span> − 4 · 1 · (− 115) = 324 + 460 = 784
</span>x₁<span> =(</span><span><span>18 + √784)/</span>2 · 1</span>=(<span>18 + 28)/2</span>=<span>46/2</span>=<span>23
</span>x₂<span><span> =(</span><span><span>18 − √784)/</span>2 · 1</span>=(<span>18 − 28)/2</span>=<span>− 10/2</span>=−<span>5
</span></span>х(х+2)=143
<span>х²+2х-143=0
</span>D<span> = </span>b²<span> − 4</span>ac<span> = 2</span>²<span> − 4 · 1 · (− 143) = 4 + 572 = 576
</span><span><span>x</span></span>₁<span><span> =(</span><span><span>− 2 + √576)/</span>2 · 1</span>=(<span>− 2 + 24)/2</span>=<span>22/2</span>=11</span>
<span><span>x</span></span>₂<span><span> =(</span><span><span>− 2 − √576)/</span>2 · 1</span>=(<span>− 2 − 24)/2</span>=<span>− 26/2</span>=−<span>13
</span></span>
228+666=894 яблок у них всего
5+3=8
555:8=69(ост3)
69*3=297(клубники)
69*5=345(винограда)
541:8=67(ост.5)
67*3=201(винограда)
67*5=335(клубники)
297+335=632(клубники)
345+201=546(винограда)
42+8=50, 44+6=50, 46+4=50, 48+2=50, 43+7=50, 45+5=50, 47+3=50, 49+1=50. Можно заметить то что во всех действиях результаты равны.
(83,2-80 1/6)*3/13=3 1/30*3/13=7/10=0,7