Question

Solve the equation x2 + + 7x= 30

Answer 1

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