670.Solve: (r– ^3 r)^2 – (r– ^3 r) – 6 = 0
a.–3, 1,b.–1, 3,c.–3, 1,d.–3, 1,671.Solve: 6x– 13^4 x+ 6 0
a.–^1861 ,–^8116
b.^1861 ,^8116
c.–^1861 ,^8116
d.–^8116 ,^1861 672.Solve: 2a – 11a + 12 0
a.–64, – ^287
b.–64,^287
c.64,^287
d.64, – ^287 ^23 ^13–3 21
2^3 i^21
2^3 ^21
2^3 ^21
2- RADICAL EXPRESSIONS AND QUADRATIC EQUATIONS–