Question

420-(458-1000÷x)+24×7=180

Answer 1

420-(458-1000÷x)+24×7=180
420-(458-1000: x)+168=180
notez paranteza (458-1000:x) cu n si exercitiul va deveni
420-n+168=180
420-n=180-168
420-n=12
n=420-12
n=408
acum stim ca n este acea paranteza. deci in loc de n vom scrie
458-1000:x=408
1000:x=458-408
1000:x=50=>x=1000:50=>x=20

Answer 2

420-(458-1000÷x)+24×7=180
420-(458-b)+24×7=180
420-c+24×7=180
420-c+168=180
420-c=180-168
420-c=12
c=420-12
c=408
458-b=408
b=458-408
b=50
1000÷x=50
x=1000÷50
x=20