Question

5a+4b=22 unde a+b=5 afla a

Answer 1

a+b=5 =>a=5-b

5(5-b)+4b=22 =>25-5b+4b=22 =>-b=-3 => b=3 si a=5-b <=> a = 5-3=2

R: a=2
     b=3

Answer 2

5a+4b=22
a+b=5
a=5-b
5b-5 +4b =22
9b = 27
b=3
a=5-b=2
V: 5×2+4×3=22
10+12=22