y=(m-2)x²+4x+(m-5) menyinggung sumbu x nilai m

y = (m−2)x​^2​​ + 4x + (m−5)
a = (m-2) b = 4 c = (m-5)

syarat menyinggung sumbu x, D = 0
b^2 - 4ac = 0
4^2 - 4 (m-2)(m-5) = 0
16 - 4 (m^2-7m+10) = 0
16 - 4m^2 - 28m - 40 = 0
-4m^2 - 28m - 24 = 0 (dikalikan -1)
4m^2 + 28m + 24 = 0 (dibagi 4)
m^2 + 7m + 6 = 0
(m+1)(m+6) = 0
m = -1 / m = -6