Question

1) -3×(-7а)×4 2) -2,4m×(-5)×3 4) 3x+15y-2x+20y 5) -0,14b+0,18b-0,23b+0,14b 6)4×(-1,2a+2,5b) 8)3×(0,4x-7)

Answer 1

1)-84а
2)36m
4)х+35у
5)-0.13b
6)-4.8а+10b
8)1.2x-21

Answer 2

1) 21а * 4 = 84а
2) 12м * 3 = 36м
4) х + 35у
5) -0,13б
6) -4,8а + б
8) 1,2х - 21

Answer 3

Let's solve the expressions one by one:

1. -3 × (-7a) × 4

To simplify this expression, we can apply the following steps:

-3 × (-7a) × 4 = 21a × 4 = 84a

Therefore, the simplified expression is 84a.

2. -2.4m × (-5) × 3

To simplify this expression, we can apply the following steps:

-2.4m × (-5) × 3 = 12m × 3 = 36m

Therefore, the simplified expression is 36m.

4. 3x + 15y - 2x + 20y

To simplify this expression, we can combine like terms:

3x - 2x + 15y + 20y = x + 35y

Therefore, the simplified expression is x + 35y.

5. -0.14b + 0.18b - 0.23b + 0.14b

To simplify this expression, we can combine like terms:

-0.14b + 0.18b - 0.23b + 0.14b = (-0.14b + 0.14b) + (0.18b - 0.23b) = 0b - 0.05b = -0.05b

Therefore, the simplified expression is -0.05b.

6. 4 × (-1.2a + 2.5b)

To simplify this expression, we can distribute the multiplication:

4 × (-1.2a + 2.5b) = -4.8a + 10b

Therefore, the simplified expression is -4.8a + 10b.

8. 3 × (0.4x - 7)

To simplify this expression, we can distribute the multiplication:

3 × (0.4x - 7) = 1.2x - 21

Therefore, the simplified expression is 1.2x - 21.