Answer:
m = ± 5
Step-by-step explanation:
Given
4² + 2² - (- 3²) = m² - (- 1²) + ()² ← evaluate exponents
noting that - 3² = - 9 and - 1² = - 1
16 + 4 - (- 9) = m² - (- 1) + 3, that is
20 + 9 = m² + 1 + 3
29 = m² + 4 ( subtract 4 from both sides )
25 = m² ( take the square root of both sides )
m = ± 5