Question

Calculează (a - b) + (c-d), stiind că a=b+12: b=c-23: c=d+7: d- 100.​

Answer 1

Răspuns:

(a-b)+(c-d)=?

(b+12-b)+(d+7-d)=

(c-23+12-c-23)+(d+7-d)=

(d+7-23+12-d+7-23)+(d+7-d)=

[d+(-4)-d+(-16)]+(d+7-d)=

[100+(-4)-100+(-16)]+(100+7-100)=

(96-84)+7=

12+7=19