To solve the problem, we first identify patterns in the given rows:

Step 1: Analyze Row 1

Row 1: 3, 15, 35, 63
These are products of consecutive odd numbers:
3 = 1×3,
15 = 3×5,
35 = 5×7,
63 = 7×9.

Step 2: Analyze Rows 3 and 4

Row 3: 7, 28, 63, 112
Each term = leftmost number × (column index)²:
7×1²=7, 7×2²=28, 7×3²=63, 7×4²=112.

Row 4: 9, 36, 81, 144
Same pattern: 9×1²=9, 9×2²=36, 9×3²=81, 9×4²=144.

Step 3: Apply Pattern to Row 2

Row 2 leftmost number = 5. Following the pattern of rows 3/4 (leftmost number × column index²):
5×1²=5, 5×2²=20, 5×3²=45, 5×4²=80.

Though the given last term (90) seems off, the intended pattern for the missing term is 5×3²=45.

Answer: 45

$\boxed{45}$

作者声明:本文包含人工智能生成内容。