Question

x2 +20x+100=25

x2-2x+1=121

Answer 1

a)  x²+20x+100=25
x²+20x+100-25=0
x²+20x+75=0
Δ= b²-4.a.c
Δ=20²- 4.1.75
Δ=400-300
Δ=100
x= (-b + ou -√Δ)/2a
x1= -20+√100): 2
x1= -20+10):2
x1=-10:2= -5
e x2= (-20-10)/2
x2= -30:2 x2=-15
x1=-5  e x2=-15

b) x²-2x+1=121
x²-2x+1-121=0
x²-2x-120=0
Δ=(-2)²-4.1.-120
Δ= 4+480
Δ=484
x1= 2+√484)2
x1=2 +22):2
x1= 24:2= 12

x2= 2-22):2
x2= -20:2=-10  x1=12 e x2=-10