[tex] \binom{a + 5b = 21} { - 3a + 2b = - 12} \times 3 \\ \\ \binom{3a + 15b = 63}{ - 3a + 2b = -12} \\ \\17b = 51 \\ b = 3 \\ = > > 3a + 15b = 63 \\ 3a + 15 \times 3 = 63 \\ 3a = 63 - 45 \\ 3a = 18 \\ a = 6[/tex]
Asta e punctul a)
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[tex] \binom{0.5x - 0.2y = 2.4}{0.2x + 0.5y = 2.7} \times 5 \: si \: \times 2 \\ \\ \binom{2.5x - y = 12}{0.4x + y = 5.4} \\ \\ 2.9x = 17.4 \\ x = 17.4 \div 2.9 \\ x = 6 \\ \\ = > > 0.4 \times 6 + y = 5.4 \\ = > > y = 5.4 - 2.4 \\ = > > y = 3[/tex]
astaa fost punctul b.
a=y
b=x
