The price will be reduced by 20%, so will become 0.8x
The tax will increase the amount by 0.0625 times
Thus:
A = 0.8x + 0.0625x
A = 0.8625x
Now, bear in mind that, when the y-axis gets intercepted, x = 0, therefore 0,3 is really the y-intercept.
and when the x-axis gets intercepted, y = 0, therefore 4,0 is the x-intercept, thus we will use this one in the point-slope form then.
Take 2points
Equation in two point form



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Option D is correct
Upwards because a is one and therefore positive