(a+b)(a-b)=a² - b²
.
(6-a)(6+a)=6² - a²=36-a
(11y-4)(11y+4)=121y² - 16
(8x+7b)(8x-7b)=64x² - 49b²
(15c³-1)(15c³+1)=(15c³)² - 1=225c⁶ - 1
51²=(50+1)(50+1)=50² + 2*50*1 + 1²=2500+100+1=2601
49*51=(50-1)(50+1)=50² - 1²=2500-1=2499
(a+b)(a-b)=a² - b²
.
(6-a)(6+a)=6² - a²=36-a
(11y-4)(11y+4)=121y² - 16
(8x+7b)(8x-7b)=64x² - 49b²
(15c³-1)(15c³+1)=(15c³)² - 1=225c⁶ - 1
.
.
51²=(50+1)(50+1)=50² + 2*50*1 + 1²=2500+100+1=2601
49*51=(50-1)(50+1)=50² - 1²=2500-1=2499