1)(с3-с2)-(3с+3с)=(с(3-2))-(3с(1+1)=(0.2•1)-(0.6•2)=0.2-1.2= -1
2)-(6х-2)+(3х-8)=-6х+2+3х-8= -3х -6= -3 •(-1.2) -6=3.6 - 6=-2.4
<span>а)х4-25х2+144=0</span>
<span>х2=у</span>
<span>у2-25у+144=0</span>
<span>По теореме Виета: у=16; у=9</span>
<span>1)х2=16 2)х2=9</span>
<span> х=-4; х=4 х=-3; х=3</span>
<span>
</span>
<span>б)у4+14у2+48=0</span>
<span>х2=у</span>
<span>у2+14у+48=0</span>
<span>По теореме Виета: у=-8; у=-6</span>
<span>1)х2=-8 2)х2=-6</span>
<span>реш.нет реш.нет</span>
<span>
</span>
<span>в)х4-4х2+4=0</span>
<span>х2=у</span>
<span>у2-4у+4=0</span>
<span>(у-2)2=0</span>
<span>у=2</span>
<span>х2=2</span>
<span>х=-√2 х=√2</span>
1a) (y - 2) + ( y + 3) = y - 2 + y + 3 = 2y + 1
(y - 2) - (y + 3) = y - 2 - y - 3 = - 5
1б) (a² - 2a + 1) + (a² - 4) = a² - 2a + 1 + a² - 4 = 2a² - 2a - 3
(a² - 2a + 1) - (a² - 4) = a² - 2a + 1 - a² + 4 = - 2a + 5
b1 = -32
q = 1/2
b6 = b1*q^(6-1) = -32 * (1/2)^5 = -32 * 1/32 = -1
S7 = b1 * (q^7 - 1) / (q - 1) = -32 * (1/128 - 1) / (1/2 - 1) = -32 * (-127/128) / (-1/2) = -2*32*127 / 128 = -127/2 = -63.5