упростите выражение
[tex]5x(2x + 3) - (x - 1)(x - 6)[/tex]
[tex](a - c) {}^{2} - c(a - 3c)[/tex]

5x(2x+3) - (x-1)(x-6) = 10x²+15x-(x²-6x-x+6) = 10x²+15x-x²+6x+x-6 = 9x²+22x-6.(a-c)² - c(a-3c) = a²-2ac+c²-ac+3c² = a²-3ac+4c².