x² + y² = (x + y)² - 2xy = 3² - 2* 4= 9 - 8 = 1
(а^2-в^2)*<span>(а^2+в^2)- получай)
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1 1/2 =3/2
22.5 =225/10 =45/2
1 2/3 =5/3
1) 3/2 : 45/2 * 5/3 =3/2 *2/45 *5/3 =(3*2*5) /(2*45*3) =5/45 =1/9
2) 6 -1/9 =5 9/9 -1/9 =5 8/9 =53/9
3) 53/9 - (-2/3) =53/9 +2/3 =(53 +2*9)/9 =(53 +18)/9 =71/9 =7 8/9
2^3x-15=2^-6; 3x-15= -6; 3x=15-6; 3x=9; x=9/3=3. Ответ: x=3.