Question

18*20-х=90 720:8+х=470 350:с=5*10 к:30=60*5

Answer 1

18*20-х=90   360-х=90   х=360-90   х=270
720:8+х=470   90+х=470   х=470-90   х=380
350:с=5*10   350:с=50   с=350:50   с=70
к:30=60*5   к:30=300   к=300*30   к=9000

Answer 2

Let's solve each of the equations step by step:

1. 18 * 20 - x = 90:

To solve for x, we'll start by simplifying the left side of the equation:

360 - x = 90

Next, we'll isolate x by subtracting 360 from both sides of the equation:

360 - 360 - x = 90 - 360

-x = -270

Finally, we'll multiply both sides of the equation by -1 to solve for x:

x = 270

So the solution is x = 270.

2. 720 / 8 + x = 470:

First, let's simplify the left side of the equation:

90 + x = 470

Next, we'll isolate x by subtracting 90 from both sides of the equation:

90 - 90 + x = 470 - 90

x = 380

So the solution is x = 380.

3. 350 / c = 5 * 10:

To solve for c, we'll start by simplifying the right side of the equation:

350 / c = 50

Next, we'll multiply both sides of the equation by c to isolate it:

350 = 50c

Then, we'll divide both sides of the equation by 50 to solve for c:

350 / 50 = c

c = 7

So the solution is c = 7.

4. k / 30 = 60 * 5:

First, let's simplify the right side of the equation:

k / 30 = 300

Next, we'll multiply both sides of the equation by 30 to isolate k:

30 * (k / 30) = 300 * 30

k = 9000

So the solution is k = 9000.

To summarize the solutions:

x = 270 x = 380 c = 7 k = 9000