Oblicz sprytnie : a) 53²-47² b) 137²-37² c) 33²-32² d) 102*98 e) 18*22 f) 37*43 Dzięki ;))

a) [latex]53^2-47^2 =(53+47)(53-47)=100 cdot 6 = 600[/latex] b) [latex]137^2-37^2 =(137+37)(137-37)=174 cdot 100 = 17400[/latex] c) [latex]33^2-32^2 =(33+32)(33-32)=65 cdot 1 = 65[/latex] d) [latex]102 cdot 98 =(100+2)(100-2) = 100^2 - 2^2 = 10000 - 4 = 9996[/latex] e) [latex]18 cdot 22 =(20-2)(20+2) = 20^2 - 2^2 = 400 - 4 =396[/latex] f) [latex]37 cdot 43 =(40-3)(40+3) = 40^2 - 3^2 = 1600 - 9 = 1591[/latex] ============== Wykorzystano wzór skróconego mnożenia [latex]a^2 - b^2 = (a+b)(a-b)[/latex]