Question

Determinati numarul necunoscut din egalitatea:
8 + 4 x {3 + 3 x [a + 4 x ( a : 2 + 2)] : 6} :31 = 12

Answer 1

Răspuns:

înmulțiret se mai poate scrie •

8 + 4 • [3 + 3 • (a + 4a : 8 + 8 ] : 6 ] : 31 = 12

8 + 4 • [3 + (a + a : 2 + 8] : 2 ] : 31 = 12

8 + 4 •(3 + a : 2 + a : 4 + 4 ) : 31 = 12

8 + 12 + 2a + a + 16 : 31 = 12

36 + 3a : 31 = 12

3a : 31 = 12 - 36

3a : 31 = -24

3a = 24 • 31

3a = 744

a = 248

Answer 2

$\it 8+4\cdot\{3+3\cdot[a+4\cdot(a:2+2)]:6\}:31=12\Big |_{-8} \Rightarrow \\ \\ \Rightarrow 4\cdot\{3+3\cdot[a+4\cdot(a:2+2)]:6\}:31=4\Big|_{:4} \Rightarrow \\ \\ \Rightarrow \{3+3\cdot[a+4\cdot(a:2+2)]:6\}:31=1\Big|_{\cdot31} \Rightarrow \\ \\ \Rightarrow 3+3\cdot[a+4\cdot(a:2+2)]:6=31\Big|_{-3} \Rightarrow 3\cdot[a+4\cdot(a:2+2)]:6=28|_{\cdot2}\Rightarrow\\ \\ \Rightarrow a+4\cdot(\dfrac{a}{2}+2)=56 \Rightarrow a+2a+8=56 \Rightarrow3a=48\Big|_{:3} \Rightarrow a=16$