Question

como eu resolvo essa conta 2x=15-x²

Answer 1

2x=15-x²
15-x²=2x
-x²=2x-15
-x²-2x=-15
-x²-2x+15=0 (-1)
x²+2x-15=0

☆=b²-4ac
☆=(2)²-4(1)(-15)
☆=4+60
☆=64

vamos achar as raízes:
1)
x=(-b+√☆)/2
x=-2+√64/2
x=-2+8/2
x=6/2
x=3

2)
x=(-b-√☆)/2
x=-2-√64/2
x=-2-8/2
x=-10/2
x=-5

espero ter ajudado