Question

Resolva as equações:

(a) x²- 112=32

(b) 6x²+1=55

(c) 8(x²-1)=7(x²+4)

(d) x(x+3)=3x+49

Answer 1

(a) x²- 112=32

x² = 32 + 112

x²= 144

x= ± √144

x= ± 12

S= ( 12 , - 12)

(b) 6x²+1=55

6x² = 55 - 1

6x² = 54

x²= 54/6

x² = 9

x= ± √9

x= ± 3

S= ( 3 , - 3)

(c) 8(x²-1)=7(x²+4)

8x² - 8 = 7x² + 28

8x² - 7x² = 28 + 8

x² = 36

x= ± √36

x= ± 6

S= ( 6 , - 6)

(d) x(x+3)=3x+49

x² + 3x = 3x + 49

x² + 3x - 3x = 49

x² = 49

x= ± √49

x= ± 7

S= ( 7 , -7)