Răspuns:
Explicație pas cu pas:
a)
1 730 : [(21 x b-33) - 4] x 20-16 = 184
1 730 : [(21 x b-33) - 4] x 20 = 184 + 16
1 730 : [(21 x b-33) - 4] x 20 = 200
1 730 : [(21 x b-33) - 4] = 200 : 20
1 730 : [(21 x b-33) - 4] = 10
(21 x b-33) - 4 = 1 730 : 10
(21 x b-33) - 4 = 173
21 × b - 33 = 173 + 4
21 × b = 177 + 33
21 × b = 210
b = 210 : 21
b = 10
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b)
[10+10x (a - 10)] : 10-10 = 10
[10+10x (a - 10)] : 10 = 10 + 10
[10+10x (a - 10)] : 10 = 20
10+10 x (a - 10) = 20 × 10
10+10 x (a - 10) = 200
10 x (a - 10) = 200 - 10
a - 10 = 190 : 10
a = 19 + 10
a = 29
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c)
1 200 - (2x+100) : 19 +2 500 = 3 500
1 200 - (2x+100) : 19 = 3 500 - 2 500
1 200 - (2x+100) : 19 = 1 000
(2x+100) : 19 = 1 200 - 1 000
2x + 100 = 200 × 19
2x = 3 800 - 100
2x = 3 700
x = 3 700 : 2
x = 1 850