Question

Afla nr a si b stiind ca a+b=375 si a+a+b=450

Answer 1

a+b = 375
a+a+b = 450 ⇔ 2a+b = 450
a = 450 - 375
a = 75
75 + b = 375
b = 375 - 75
b = 300

Answer 2

$a+b=375 \\ a+a+b=450 \\ 2a+b=450 \Rightarrow b=450-2a \\ a+450-2a=375 \Rightarrow a-2a=375-450 \Rightarrow -a=-75 \Rightarrow a=75 \\ b=450-2a \Rightarrow b=450-2 \cdot 75 \Rightarrow b=450-150 \Rightarrow b=300 \\ \boxed{a=75;b=300}$