<span><span>(<span><span>a2</span>−<span>b2</span>+ab−2</span>)</span><span>(<span><span>a2</span>−<span>b2</span>−ab−2</span>)</span>−<span><span>(<span><span>a2</span>−<span>b2</span>−2</span>)</span>2</span>=</span>Возведение в степень:<span><span>(<span><span>a2</span>−<span>b2</span>+ab−2</span>)</span><span>(<span><span>a2</span>−<span>b2</span>−ab−2</span>)</span>−<span>(<span><span>a4</span>−2<span>a2</span><span>b2</span>−4<span>a2</span>+<span>b4</span>+4<span>b2</span>+4</span>)</span>=</span>Раскрытие скобок:<span><span><span>a4</span>+<span>a2</span><span>(<span>−1</span>)</span><span>b2</span>+<span>a3</span><span>(<span>−1</span>)</span>b+<span>a2</span><span>(<span>−2</span>)</span>−<span>b2</span><span>a2</span>+<span>b4</span>+<span>b3</span>a+2<span>b2</span>+<span>a3</span>b+a<span>b3</span><span>(<span>−1</span>)</span></span><span>+<span>a2</span><span>b2</span><span>(<span>−1</span>)</span>+ab<span>(<span>−2</span>)</span>−2<span>a2</span>+2<span>b2</span>+2ab+4−<span>a4</span>+2<span>a2</span><span>b2</span>+4<span>a2</span>−<span>b4</span>−4<span>b2</span>−4=</span></span><span><span>a2</span><span>(<span>−1</span>)</span><span>b2</span>−<span>b2</span><span>a2</span>+<span>b3</span>a+a<span>b3</span><span>(<span>−1</span>)</span>+<span>a2</span><span>b2</span>=</span><span>−<span>a2</span><span>b2</span>−<span>b2</span><span>a2</span>+<span>b3</span>a−a<span>b3</span>+<span>a2</span><span>b2</span>=</span>−a2b2
Задуманное число х, тогда
(Х+1)*2::3-4=5
(Х+1)*2:3=5+4
(Х+1)*2:3=9
(Х+1)*2=9*3
(Х+1)*2=27
(Х+1)=27:2
Х+1=13,5
Х=13,5-1
Х=12,5
Надеюсь помогла! №1 не могла решать.