1) 5(x-y)=5(2,5-4,5)=5×(-2)=-10
2) 3(x+y)=3(2,5+4,5)=3×7=21
3) (5x-y)=5×2,5-4,5=12,5-4,5=8
4) (3x+y)=3×2,5+4,5=7,5+4,5=12
1) 5(x-y)=5(2,5-4,5)=5×(-2)=-10
2) 3(x+y)=3(2,5+4,5)=3×7=21
3) (5x-y)=5×2,5-4,5=12,5-4,5=8
4) (3x+y)=3×2,5+4,5=7,5+4,5=12