<span>f '(x) = [(-40x +11)(7x - 9) - 7(-4x +3)(5x + 1)]/(7x - 9)2</span>
<span>= [(-280x2<span> + 360x + 77x - 99) - 7(-20x</span>2<span> - 4x + 15x + 3)]/(7x - 9)</span>2</span>
<span>= [(-280x2<span> + 437x - 99) + (140x</span>2<span> + 28x - 105x - 21)]/(7x - 9)</span>2</span>
<span>= (-140x2<span> +360x - 120)/(7x - 9)</span><span>2
</span></span>
i think thats how you would solve it
hope this helps tho:)
Answer: $222.73
===========================================
Work Shown:
x = pre-GST price
10% of x = 0.10x = tax amount
x + 0.10x = 1.10x = post-GST price = 245
1.10x = 245
x = 245/1.10
x = 222.7272 approximately
x = 222.73 is the price before tax.
------------
Check:
10% of 222.73 = 0.10*222.73 = 22.273 = 22.27
The tax amount ($22.27) is added to the pre-GST price to get
22.27+222.73 = 245
which matches the post-GST price mentioned.
The answer is confirmed.
Or another way to confirm the answer is to calculate this
1.10*222.73 = 245.003 = 245
Ok sure—————-_______—-____
