1)9(9-5x)^2+17(9-5x)+8=0 2)8(10-3x)^2-5(10-3x)-3=0

Question

1)9(9-5x)^2+17(9-5x)+8=0

2)8(10-3x)^2-5(10-3x)-3=0

Answer 1

9-5x = m

9m^2 + 17m + 8 = 0

D = 289 - 72*4 = 1

m1 = (-17 - 1)/ 18 = -1

m2 = (-17 + 1)/ 18 = -8/9

 

9 - 5x = -1

x = 2

 

9 - 5x = -8/9

x = 89/45

 

 

 

10 - 3x = n

8n^2 - 5n - 3 = 0

D = 25 + 96 = 121

n1 = (5 - 11)/ 16 = -3/8

n2 = (5 + 11)/ 16 = 1

 

10 - 3x = -3/8

x  = 21/24 = 7/8

 

10 - 3x = 1

x = 3