Question

已知a,b满足(a-b)²+丨ab+6丨=0 （1）如果x=2a+3b+3,求此时x的值

Answer 1

|(a+b)×(a-b)|=|a+b|.|a-b|.sin

.=5*5*24/25.=24.∴|(a+b)×(a-b)|=24.7 (a+b)(a-b)=a^2-