: 1. Вычислите
1) -6 ⋅ 1,2 ⋅ (-5);
2) 0,4 ⋅ 19 - 25;
3) 1,25 ⋅ (-8) ⋅ (-0,5) ⋅ (-2);
4) 4,78 ⋅ (-4) ⋅ 25 + 500;
5) 5 ⋅ (-2,6) - 0,6 ⋅ (-100);
2. Упростите выражение и подчеркните его коэффициент:
1) -3,2 ⋅ 6x;
2) -0,8y ⋅ (-07);
3) 5а ⋅ (-1,4b) ⋅ 0,6c;
4) 1,5 ⋅ (-x) ⋅ 28 ⋅ y;
5) -3 c ⋅ 3,3 ⋅ b.
5. Упростите выражение -1,25c ⋅ 8d и найдите его значение, если c = -1,2 d =9.
1)=-6×(-5)×1,2=30×1,2=30/1×12/10=30/1×6/5=180/5=36
2)=4/10×19/1-25=2/5×19/1-25=38/5-25=7,6-25=-17,4
3)=1,25×(-8)×1=125/100×(-8/1)=25/20×(-8/1)=-200/20=-10
4)=4,78×(-100)+500=-478+500=22
5)=-13-(-60)=-13+60=47
2.
1)=-19,2х
2)=0,56у
3)=3ас×(-1,4b)=-4,2abc
4)=42×(-x)×y=-42xy
5)=-9,9bc
5. =-10dc=-10×9×(-1,2)=-10×(-10,8)=108