Question

Sa se afle doua numere stiind ca suma lor este 95 si diferenta lor 40.
Cat ai repede! Multumesc :)

Answer 1

a+b=95;     a-b=40;
Rez:a+b+a-b=95+40
2a=135;
a=135:2;
a=67,5;
b=95-67,5;
b=27,5;
Raspuns:a=67,5
b=27,5

Answer 2

$\left \{ {{x+y =95 } \atop {x-y=40}} \right. \\ x=95-y \\ 95-y-y=40 \\ 95-2y=40 \\ 2y=55 \\ y= \frac{55}{2} \\ x- \frac{55}{2} =40 \\ 2x-55=80 \\ 2x=25 \\ x= \frac{25}{2}$