2B = √ 245 - √ 3 - √ 147 - √ 5 2B = radical (radical 245 - radical 3) - radical (radical 147 - radical 5) Original title: Given a + B = radical (7 radical 5-radical 3), A-B = radical (7 radical 3-radical 5), find: ① AB, ② A & sup2; + B & sup2; And how to make a complete root with the computer Other people don't understand

2B = √ 245 - √ 3 - √ 147 - √ 5 2B = radical (radical 245 - radical 3) - radical (radical 147 - radical 5) Original title: Given a + B = radical (7 radical 5-radical 3), A-B = radical (7 radical 3-radical 5), find: ① AB, ② A & sup2; + B & sup2; And how to make a complete root with the computer Other people don't understand


a^2+b^2+2ab=7√5-√3
a^2+b^2-2ab=7√3-√5
By subtracting the two formulas, 4AB = 8 √ 5-8 √ 3
So AB = 2 √ 5-2 √ 3
Substituting the above formula
a²+b²=3√5-3√3