Question

Calculați produsul nr a b c știind că sunt îndeplinite in acelasi timp următoarele condiții.
2×a+15=23
3×b+9=36
a×c-11×b=1

Answer 1

a×b×c= x

a = 2×a+15=23
= 2a + 15 = 23
2a = 23 - 15 = 8
a = 8:2
a = 4
Verificare: 2×4+15=8+15=23

b = 3×b+9=36
= 3b+9=36
3b = 36 - 9 = 27
b = 27 : 3
b = 9
Verificare: 3×9+9=27+9=36

a×c-11×b=1
4×c-11×9=1
4c-99=1
4c = 1 + 99
4c = 100
c = 100 : 4
c = 25

a × b × c = x
4 × 9 × 25 = 36 × 25 = 900

Answer 2

2×a+15=23
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2×a=23-15
2×a=8
a=8:2
a=4

3×b+9=36
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3×b=36-9
3×b=27
b= 27:3
b= 9

a×c-11-b=1
4×c-11-9=1
_____
4×c-11=9+1
4×c-11=10
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4×c=11+10
4×c=21
c=21:4
c=5 (rest 1)
4×9×5+1=36×5+1=180+1=181