Question

X^2+4x=7 using the quadratic formula?

Answer 1

When you have
ax^2+bx+c=0
x=$\frac{-b+/- \sqrt{b^{2}-4ac} }{2a}$


1x^2+4x=7
minus 7
1x^2+4x-7=0
a=1
b=4
c=-7
sub

x=$\frac{-4+/- \sqrt{4^{2}-4(1)(-7)} }{2(1)}$
x=$\frac{-4+/- \sqrt{16+28} }{2}$
x=$\frac{-4+/- \sqrt{44} }{2}$
x=$\frac{-4+/- 2\sqrt{11} }{2}$
x=$-2+/- \sqrt{11}$

x=$-2+ \sqrt{11}$ or $-2- \sqrt{11}$