Question

Я не могу это решить. Помогите пожалуйста дам 55балов 1) (−2,87−(−4,34)) ÷ 0,6 + 0,5 × (−1,4)= 2) 4 (−2,5х + 4) – (18 – 9,4х) – 0,5 (4,4х +4)=при х = 11/4 3) 3 (6х + 4у) – 2 (2х + 7у), при (у – 7х) = 6,4

Answer 1

Ответ:1) (-2,87-(-4,34)):0,6+0,5*(-1,4)=1,47:0,6-0,7=2,45-0,7=1,75

2) 4(-2,5х+4)-(18-9,4х)-0,5(4,4х+4)=-10х+16-18+9,4х-2,2х-2=-2,8х-4     -2,8*11/4-4=-7,7-4=-11,7

3) 3(6х+4у)-2(2х+7у)=18х+12у-4х-14у=14х-2у =-2(у-7х)     -2*6,4=-12,8 

Пошаговое объяснение:

Answer 2

1) (−2,87−(−4,34)) ÷ 0,6 First, let's simplify the expression within the brackets: (-2.87 - (-4.34)) = -2.87 + 4.34 = 1.47 Now we can evaluate the division: 1.47 ÷ 0.6 = 2.45 2) 4 (-2.5х 4) – (18 – 9.4х) – 0.5 (4.4х 4)=при х = 11/4 Let's substitute x = 11/4 into the expression and simplify: 4 (-2.5 * 11/4) - (18 - 9.4 * 11/4) - 0.5 (4.4 * 11/4) =-27.5 - (18 - 25.9) - 0.5 (48.4/4) =-27.5 - (-7.9) - 0.5 (12.1) =-27.5 + 7.9 - 6.05 =-15.65 3) 3 (6х 4у) – 2 (2х 7у), при (у – 7х) = 6.4 By substituting у - 7х = 6.4 into the expression, we can evaluate it further: 3 (6х 4у) - 2 (2х 7у) =3 (6х 4(у - 7x)) - 2 (2х 7у) =3 (6x + 4у - 28x) - 2 (2х + 7у) =3 (-22x + 4у) - 2 (2х + 7у) =-66x + 12у - 4х - 14у =-70x - 2у So, when у - 7х = 6.4, the expression simplifies to -70x - 2у.