Question

найдите а^2+в^2 , если а+в =10 , ав=-7​

Answer 1

$a+b=10 |()^2\\a^2+2ab+b^2=100\\a^2+2cdot(-7)+b^2=100\\a^2-14+b^2=100\\a^2+b^2=100+14\\a^2+b^2=114$