Question

1) Resolva
a) (x-4)(x-5)=20
b) (2y-1)^2=1

Answer 1

A)
X²-5x-4x+20=20
X²-9x+20-20=0
X²-9x=0

b²-4ac
(-9)²-4.1.0
81

X= (9±9)/2
X1=9+9/2=18/2=9
X2=0

B)
2y²-2.2y.1+(-1)²=1
2y²-4y+1=1
2y²-4y+1-1=0
2y²-4y=0

b²-4ac
(-4)²-4.2.0
16

X=(4±4)/2.2
X1=4+4/4=8/4=2
X2=0