Question

已知a=二分之一，b=三分之二，求式子5a【(a²+4ab+4b²）÷（a+2b）+(9a²-16b²)÷(3a-4

要答案和计算过程

Answer 1

5a[(a²+4ab+4b²）÷（a+2b）+(9a²-16b²)÷(3a-4b)]
=5a[(a+2b)²÷（a+2b）+(3a+4b)(3a-4b)÷(3a-4b)]
=5a[(a+2b)+3a+4b]
=5a[4a+6b]
=20a²+30ab
=20(1/2)²+30(1/2)(2/3)
=5+10
=15