Explanation:
a+b=4
ab=1(−21)=−21
−1,21
−3,7
−1+21=20
-3+7=4
a=−3
b=7
(m²−3m)+(7m−21)
m(m−3)+7(m−3)
(m−3)(m+7)
Hope this is correct
Answer: m =(-4-√96)/2=-2-2√ 6 = -6.899
m =(-4+√96)/2=-2+2√ 6 = 2.899
