Question

Спростити вираз (5a-2b)2- (3a+2b)(3a-2b) -20ab

Answer 1

${(5a - 2b)}^{2} - (3a + 2b)(3a - 2b) - 20ab = {25a}^{2} - 20ab + {4b}^{2} - {9a}^{2} + {4b}^{2} - 20ab = {16a}^{2} - 40ab + {16b}^{2} = 8( {2a}^{2} - 5ab + {2b}^{2} )$