1) 2*1/9 + (3/5)^(-2) - 1 = 2/9 + 25/9 - 1 = 27/9 - 1=3-1 = 2
2) возведем обе части в квадрат:
40 - x² = 9x²
x≥0 это система
10x² = 40
x≥0
x = 2 или x = -2
x≥0 ⇒x=2
3) 7^(x-1) (7³ + 2) = 345
7^(x-1)* 345 = 345
7^(x-1) = 1 , т.е. 7^0
x-1=0
x=1
4) log (3) ((2x+4)/2) = log (3)5
(2x + 4)/2 = 5
2x = 6
x = 3
6) 4x - 7> 0 (т.к. 1 = 5^0)
4x > 7
x>7/4
7) 24sin 56°/sin 56° = 24 (формула синуса двойного угла)
8) 3x - π/6 = π + 2πn
3x = π/6 + π + 2πn
3x = 7π/6 + 2πn
x = 7π/18 + 2πn/3
9) 12* π/2 - π/3 - (π - π/4) + 2*0 = 6π - π/3 - 3π/4 = (72π-4π-9π)/12 = 59π/12