Question

Resolva em R cada equação
a)|x²-7x+9|=3
b)|2x-1|=-x+3

Answer 1

Oi Isisfernanda

a) 

|x² - 7x + 9| = 3

x² - 7x + 6 = 0
delta
d² = 49 - 24 = 25
d = 5
x1 = (7 + 5)/2 = 12/2 = 6
x2 = (7 - 5)/2 = 2/2 = 1

|x² - 7x + 9| = -3

x² - 7x + 12 = 0
delta
d² = 49 - 48 = 1
d = 1

x1 = (7 + 1)/2 = 8/2 = 4
x2 = (7 - 1)/2 = 6/2 = 3

S = (1,3,4,6)

b) 

|2x - 1| = -x + 3

2x - 1 = -x + 3
2x + x = 3 + 1
3x = 4
x = 4/3

|2x - 1| = x - 3

2x - 1 = x - 3
2x - x = 1 - 3
x = -2 

S = (-2, 4/3)