Question #70e44

1 Answer
Apr 16, 2017

x in {+5, +2}

Explanation:

Case 1: the absolute value is positive

3m = m^2 - 10

0 = m^2 - 3m - 10

0 = (m - 5)(m + 2)

m = 5 or -2

Case 2: the absolute value is negative

3m = -(m^2 - 10)

3m = -m^2 +10

m^2 + 3m - 10 = 0

(m + 5)(m - 2) = 0

m = -5 or 2

However, the negative solutions are extraneous because the left hand side would be negative while the right hand side would be positive (by the definition of |a|).

Hopefully this helps!