Решение задания приложено
5sinx + 12cosx
r = √(a^2 + b^2) = √(5^2 + 12^2) = 13
cost = 5/13
sint = 12/13
t= arcsin 12/13
5/13*sinx + 12/13*cosx = 13*(5/13sinx + 12/13cosx) =
= 13 sin (x + arcsin 12/13)
48•(х-3)-3х+4
48х²-144-3х+4х
48²-147х+4
5-100x-90=-3
-85-100x=-3
-100x=-3+85
-100x=82
x=-0.82
0,5(4 - 2y) = y - 1,8
2 - y = y - 1,8
y + y = 2 + 1,8
2y = 3,8
y = 1,9