30×3+1×3=?×3;50×5+6×5=?×5;100×7+10×7+3×7=???×?;90×6+2×6=??×?

30*3+1*3=?*390+3 =?*3?=93:3?=3150×5+6×5=?×5;250+30=?*5?=280:5?=56100×7+10×7+3×7=???×?;700+70+21= ???*?791=???*?791= 113*790×6+2×6=??×?540+12=??*?552= 69*8