Question

1)0,6(4х-12)-0,4(5х-7) при х=4 1:6 2)5 1:7(у-7)-3 3:7(14-у) при у=-0,4

Answer 1

1) х=4; 0,6*(4*4-12)-0,4*(5*4-7)=0,6*4-0,4*13=2,4-5,2=-2,8
второй не поняла прости

Answer 2

To evaluate the expressions, let's substitute the given values into the expressions and perform the calculations.

1. 0.6(4x - 12) - 0.4(5x - 7) when x = 4: Substitute x = 4 into the expression: 0.6(4(4) - 12) - 0.4(5(4) - 7)

   Simplify inside the parentheses: 0.6(16 - 12) - 0.4(20 - 7)

   Perform the multiplications: 0.6(4) - 0.4(13)

   Simplify further: 2.4 - 5.2

   Subtract: -2.8

   Therefore, the value of the expression is -2.8 when x = 4.

2. 5 ÷ 7(y - 7) - 3 ÷ 7(14 - y) when y = -0.4: Substitute y = -0.4 into the expression: 5 ÷ 7(-0.4 - 7) - 3 ÷ 7(14 - (-0.4))

   Simplify inside the parentheses: 5 ÷ 7(-0.4 - 7) - 3 ÷ 7(14 + 0.4)

   Perform the additions and subtractions: 5 ÷ 7(-7.4) - 3 ÷ 7(14.4)

   Perform the divisions: -1.057 - 0.6

   Subtract: -1.657

   Therefore, the value of the expression is -1.657 when y = -0.4.