Răspuns: a = 5
Explicație pas cu pas:
[tex] \bf 460 - [ 6 \times 8 + (3 \times a + 15) + 7 \times 8 ] \times 3 = 58 [/tex]
[tex] \bf 460 - [ 48 + (3 \times a + 15) + 56 ] \times 3 = 58[/tex]
[tex] \bf [ 48 + (3 \times a + 15) + 56 ] \times 3 = 460 - 58[/tex]
[tex] \bf [ 48 + (3 \times a + 15) + 56 ] \times 3 = 402 [/tex]
[tex] \bf 48 + (3 \times a + 15) + 56 = \frac{402}{3} [/tex]
[tex] \bf 48 + (3 \times a + 15) + 56 = 134[/tex]
[tex] \bf 48 + (3 \times a + 15) = 134 - 56[/tex]
[tex] \bf 48 + (3 \times a + 15) = 78[/tex]
[tex] \bf 3 \times a + 15 = 78 - 48[/tex]
[tex] \bf 3 \times a + 15 = 30[/tex]
[tex]\bf 3 \times a = 30 - 15[/tex]
[tex]\bf 3 \times a = 15[/tex]
[tex] \bf a = \frac{15}{3} \Rightarrow \red{ \boxed{ \bf a = 5} } [/tex]
