1)(7+5)2=12²=12×12=144
2)(7+5)×(7-5)=12×2=24
3)(7-5)2=2²=2×2=4
4)7²+2×7×5+5²=(7×7)+2×7×5+(5×5)=49+70+25=144
5)7²-5²=(7×7)-(5×5)=49-25=74
6)7²+5²-2×7×5=(7×7)+(5×5)-2×7×5=49+25+70=144
