Y'(x) = 3*(5x²+7x-9)² * (10x + 7) = 3( 25x^4 +70x^3 - 41x^2 - 126x + 81)(10x+7) = 3(250x^5 + 700x^4 - 410x^3 - 1260x^2 + 810x + 175x^4 + 490x^3 - 287x^2 - 882x + 567) = 3( 250x^5 + 875x^4 + 80x^3 - 1547x^2 - 72x + 567) = 750x^5 + 2625x^4 + 240x^3 - 4641x^2 - 216x + 1701