Standard form: Ax + By = C
First make slope intercept
y = 1/3(x - 6) + 9
y = 1/3x - 2 + 9
y = 1/3x + 7
Now make standard form
Subtract 7 and y
1/3x - y = -7
Get rid of fraction
Multiply all by 3
Solution: x - 3y = -21
The $72.99 backpack is a better choice to buy because
The $84.99 backpack for 1/3 off is approximately $28.3299 (about $28.33)
And the $72.99 backpack for 25% off is $18.2475 (about $18.25)
So since $18.25 < $28.33, the $72.99 backpack has a cheaper price.
Y=-4x-8, just graph it and plot points
The answer to this problem would be A
The appropriate choice is ...
C) -x^3 + x^2 - 1
