How do you solve the quadratic #7k^2+7=-140# using any method?
1 Answer
Sep 4, 2016
Explanation:
Begin by isolating
#k^2#
#7k^2=-140-7=-147#
#rArrk^2=(-147)/7=-21# now take the
#color(blue)"square root"# of both sides
#rArrsqrt(k^2)=+-sqrt(-21)rArrk=+-sqrt(-21)# Now
#sqrt(-21)=sqrt(-1xx21)=sqrt(-1)xxsqrt21=i sqrt21#
#rArrk=+-isqrt21#
