1) 1+3(4-0,2а)+5(1,2а-4) = 1+12-0,6а+6а-20 = 5,4а-7 (1)
2) 9x^2 = 4(2x+1) 9x^2 =8x+4 9x^2-8x-4 = 0 x = 8+-V(64+4*4*9) / 2*9 = 8 +- 2V52 / 18.
x max = 4 + V52 / 4 (1)
3) (16*43^-3 - 1.5^0 - 2 / 2^-2)*(-2.5)^-1 = 16/4^3 - 1 - 2*2^2 /1)*(-1 / 2.5) = ((1-4-32) / 4)*(-2/5) =
=(-35/4)*(-2/5) = 70/20 = 3.5 (2)
4) (1/(a-b)+1/b) / a / b + 1 /(a - b) = ((b+a-b)*b) / b*(a-b)*a + 1 /(a - b) = 2 /(a - b) (1)
5) x - 5 = -1 / x x^2 - 5x + 1 = 0 x1 =2,5 + V21/2 = 0,21 x2 = 2,5 - V21/2 = 4,79
y1 = -0,21 y2 = -4,79 - это 4 четверть (3)