Question

A) 4,2-84+2,3x-46+x при x=20 б) 2,1x+6,3-2,4x-6,2-5 при x=-3 в) 3,2(x-3,2)+5,5(x-2,2) при x=3.2 г) 6,3(x+2,4)-9,1(x+1,4) при x= -1,4 20 балллллловв

Answer 1

Ответ:

Пошаговое объяснение:

a) 4,2-84+2,3x-46+x=3.3х-125.8=3.3*20-125.8= 66-125.8=-59.8

б) 2,1x+6,3-2,4x-6,2-5=-0.3х-4.9=-0.3+(-3)-4.9=0.9-4.9=-4 \

в) 3,2(x-3,2)+5,5(x-2,2)=3.2х-10.24+5.5х- 12.1=8.7х-22.34=8.7*3.2-22.34=27.84-22.34=5.5

г) 6,3(x+2,4)-9,1(x+1,4)=6.3х+15.12-9.1х-12.74=2.38-2.8х=2.38-2.8*(-1.4)=2.38+3.92=6.3

Answer 2

To find the values of the expressions for the given values of x, let's substitute the values and perform the calculations:

A) 4.2 - 84 + 2.3x - 46 + x, when x = 20 Replace x with 20: 4.2 - 84 + 2.3(20) - 46 + 20

Now, perform the calculations step by step: 4.2 - 84 = -79.8 2.3(20) = 46 -79.8 + 46 = -33.8 -33.8 + 20 = -13.8

So, the result for A) is: -13.8

B) 2.1x + 6.3 - 2.4x - 6.2 - 5, when x = -3 Replace x with -3: 2.1(-3) + 6.3 - 2.4(-3) - 6.2 - 5

Now, perform the calculations step by step: 2.1(-3) = -6.3 -2.4(-3) = 7.2 -6.3 + 6.3 = 0 0 - 6.2 = -6.2 -6.2 - 5 = -11.2

So, the result for B) is: -11.2

C) 3.2(x - 3.2) + 5.5(x - 2.2), when x = 3.2 Replace x with 3.2: 3.2(3.2 - 3.2) + 5.5(3.2 - 2.2)

Now, perform the calculations step by step: 3.2 - 3.2 = 0 3.2 - 2.2 = 1 3.2(0) = 0 5.5(1) = 5.5 0 + 5.5 = 5.5

So, the result for C) is: 5.5

D) 6.3(x + 2.4) - 9.1(x + 1.4), when x = -1.4 Replace x with -1.4: 6.3(-1.4 + 2.4) - 9.1(-1.4 + 1.4)

Now, perform the calculations step by step: -1.4 + 2.4 = 1 -1.4 + 1.4 = 0 6.3(1) = 6.3 -9.1(0) = 0 6.3 - 0 = 6.3

So, the result for D) is: 6.3

Adding up the points: A) -13.8 B) -11.2 C) 5.5 D) 6.3

Total points = -13.8 - 11.2 + 5.5 + 6.3 = -13.2

The total points earned are -13.2.