Answer:
x^2+7x=30
x^2+7x-30=0
Here a=1,b=7 and c=-30
Now,
Discriminant(D)=b^2-4ac
=7^2-4×1×(-30)
=49+120=169
By applying Quadratic formula
x=-b+- root over b^2-4ac÷2a
=-7+- root over D ÷ 2×1
=-7 +- root over 169 ÷2
=-7 +- 13 ÷2
Now,
Either x=-7+13÷2=6÷2=3
Or x=-7 -13 ÷2=-20÷2=-10
Hence, ans is (C) x=-10 and x=3
