63²(63+63)-27²(27+27)=180
23²(23+23)-13²(13+13)=72
1) 63² - 27² = ( 63 - 27)(63 + 27) = 36 * 90 = 3240
2) 23² - 13² = (23 + 13)(23 - 13) = 36 * 10 = 360
63²(63+63)-27²(27+27)=180
23²(23+23)-13²(13+13)=72
1) 63² - 27² = ( 63 - 27)(63 + 27) = 36 * 90 = 3240
2) 23² - 13² = (23 + 13)(23 - 13) = 36 * 10 = 360