AB-AC stiind ca a=7 si b-c=100
5xy+5xz+21stiind ca x=4si y+z=100 ​


Răspuns :

Răspuns:

AB-AC=A(B-C)=7x100=700

5xy+5xz+21=5x(y+z)+21=5x4x100+21=2000+21=2021

Explicație pas cu pas:

Răspuns:

a)AB-AC=100

A(B-C)

7•100=700

.

b) 5xy+5xz+21=2021

5x(y+x)+21

5•4•100+21

20•100+21

2000+21=2021

.

Succes! (•‿•)