Răspuns:1. 240 : (4 x 3 + 1 - 7) = 240 : (12+1-7) = 240: 6 = 40
Syonys avatar
3. a+b=361
a-b=25
⇒a=b+25
b+25+b=361
2b+25=361
2b=361-25
2b=336
b=336:2
b=168
a=b+25
a=168+25
a=193
Verificare:
a+b=361
193+168=361
a-b=25
193-168=25
Syonys avatar
4. 42 49 56 63
Syonys avatar
5. 52*(2x-5)=156
52*2x-52*5=156
104x-260=156
104x=156+260
104x=416
x=416/104
x=4
Explicație pas cu pas: