Question

Stiind ca ax+ay - 8 =100
Si x+y =12 , calculati a-(x+y-7)
Va rog!

Answer 1

$ax+ay-8=100 \Leftrightarrow ax+ay=108 \Leftrightarrow a(x+y)=108 \Leftrightarrow a*12=108 \\ \Rightarrow a=9. \\ \\ a-(x+y-7)=9-(12-7)=9-5=4.$