Обе части равенства делим на (4^x = 2^(2x)) ... или на (25^x = 5^(2x))
оба эти выражения никогда не равны нулю...
2^(2x-2x) - 5^x*2^(x-2x) - 6*5^(2x) / (2^(2x)) = 0
1 - (5/2)^x - 6*(5/2)^(2x) = 0
квадратное уравнение относительно (5/2)^x
6*((5/2)^x)^2 + (5/2)^x - 1 = 0
D = 1+4*6 = 5²
(5/2)^x = (-1-5) / 12 = -1/2 ---посторонний корень)))
(5/2)^x = (-1+5) / 12 = 1/3
х = log(2/5) (3)
А)<span><span>(<span><span>x2</span>+x</span>)</span><span>(<span>49−<span>x2</span></span>)</span>=</span>Раскрытие скобок:<span><span>x2</span>49+<span>x4</span><span>(<span>−1</span>)</span>+x49+<span>x3</span><span>(<span>−1</span>)</span>=</span><span>49<span>x2</span>−<span>x4</span>+49x−<span>x3</span>=</span><span>−<span>x4</span>−<span>x3</span>+49<span>x2</span>+49x</span>Ответ: <span>−<span>x4</span>−<span>x3</span>+49<span>x2</span>+49x
В)</span><span><span>(<span><span>x2</span>−7</span>)</span><span>(<span><span>x2</span>+18</span>)</span>=</span>Раскрытие скобок:<span><span>x4</span>+<span>x2</span>18−7<span>x2</span>−126=</span><span><span>x4</span>+11<span>x2</span>−126</span>Ответ: <span><span>x4</span>+11<span>x2</span>−126
Д)</span><span><span>(<span><span>x2</span>−3<span>x2</span></span>)</span><span>(<span><span>x2</span>+7</span>)</span>=</span>Приведение подобных:<span><span>(<span>−2<span>x2</span></span>)</span><span>(<span><span>x2</span>+7</span>)</span>=</span>Раскрытие скобок:<span>−2<span>x4</span>−14<span>x2</span></span>Ответ: <span><span>−2<span>x4</span>−14<span>x2
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=1-1/корень(3) ответ такой будеть
-0,3а вроде бы
Там а-а=0, а потом 6,2а-6,5а=-0,3а.
X^2+3x=0
x(x+3)=0
x=0 или x+3=0
х= -3