Question

(580-x):4=100... 40:x+70=90

Answer 1

1)
(580-x):4=100
(580-x)=100×4
(580-x)=400
580-x=400
x=580-400
x=180
2)
40:x+70=90
40:x=90-70
40:x=20
x=2

Answer 2

1. х=180 (100 умножаем на 4; 580-400=180)
2. х=2 (от 90 отнимаем 70; 40:20=2)

Answer 3

To solve the equations, let's first work with each equation separately.

1. (580 - x) / 4 = 100:

To solve for x, we need to isolate x on one side of the equation. To do that, we'll first get rid of the division by 4 by multiplying both sides of the equation by 4:

4 * [(580 - x) / 4] = 4 * 100

This simplifies to:

580 - x = 400

Now, to isolate x, we'll subtract 580 from both sides:

-x = 400 - 580

This simplifies to:

-x = -180

Finally, to solve for x, we need to multiply both sides by -1 (to get rid of the negative sign):

x = 180

So the value of x in the first equation is x = 180.

2. 40 / x + 70 = 90:

To solve for x, we first need to get rid of the addition by 70 and then the division by x. Let's start by subtracting 70 from both sides:

40 / x = 90 - 70

This simplifies to:

40 / x = 20

Next, to isolate x, we'll get rid of the division by multiplying both sides by x:

x * (40 / x) = x * 20

The x on the left side cancels out, leaving:

40 = 20x

Now, to find the value of x, divide both sides by 20:

x = 40 / 20

This simplifies to:

x = 2

So the value of x in the second equation is x = 2.

In summary:

1. x = 180
2. x = 2