Question

PLEASE HELP

Which equation shows the quadratic formula used correctly to solve 7^2 = 9 + x for x?

Answer 1

7x²=9+x
so
for
0=ax²+bx+c


`x=(-b+/-√(b^2-4ac))/(2a)`
so

7x²=9+x
mins 9 from both sides and minus x
7x²-1x-9=0
a=7
b=-1
c=-9



`x=(-(-1)+/-√((-1)^2-4(7)(-9)))/(2(7))`

`x=(1+/-√((-1)^2+4(7)(9)))/(2(7))`
so the 4th one