Question

ayudaaaaa por favor!!!

Answer 1

1) 4x^2+28=428
4x^2=428-28
4x^2=400
x^2=100

x1= -10  x2=10



2) x^2+x=30
 x^2+x-30=0


X= -1 +-√1² -4(1)(-30)/2(1)
X=-1+-√1+120/2
X=-1+-√121/2
X=-1+-11/2

X=-1+11/2

X=-1-11/2

X₁=-6
X₂=5



3)x²-x=30
x²-x-30=0

X= -1 +-√1² -4(1)(-30)/2(1)
X=-1+-√1+120/2
X=-1+-√121/2
X=-1+-11/2

x=1-11/2

x=1-11+2

x₁=6
x₂=-5