Answer:
Step-by-step explanation:
Use identity : (a + b)² =a² + 2ab + b²
49m⁴ + 140m² + 100 = 7²(m²)² + 2 * 7m² * 10 + 10²
= (7m²)² + 2 *7m²*10 + 10²
= (7m² + 10)²
= (7m² + 10)(7m² + 10)
The answer will be 30cm
Because 40 divided by 4 is 10 and times it by 3
