6.--the anglethrough which the conic with each equation should be rotated. Then write the equation in standard form.

13x - 8xy + 7y - 45=0

a= 63; (x')/9 + (y')/3=1

b= 63; (x')/9 - (y')/3=1

c= 297; (x')/9 + (y')/3=1

d= 63; 13(x') - 8xy + 7(y')=45

7.--the anglethrough which the conic with each equation should be rotated. Then write the equation in standard form.

16x - 24xy + 9y -30x - 40y=0

a= 53; (x')=2y'

b= 307; (y')=2x'

c= 53; (y')=2x'

d= 53;(x') + (y')=0