Factor –7x3 + 21x2 + 3x – 9 by grouping. What is the resulting expression? (3 – 7x)(x2 – 3)
(7x – 3)(3 + x2)
(3 – 7x2)(x – 3)
(7x2 – 3)(3 + x)

The answer is the third option

(3–7x²)(x–3)

Step-by-step explanation:

If you apply the distributive property in (3–7x²)(x–3), you obtain:  

3x-9-7x²(x)+21x²

3x-9-7x³+21x²

When you order the expression, you have:  

-7x³+21x²+3x-9

Then, the answer is (3–7x²)(x–3)

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.

step-by-step explanation:

here's what happens:

1) the graph of f   = x^2 is shifted 2 units to the right.

2) the resulting graph is reflected in the x-axis, so that the parabola now opens down.

3) this final result is transformed up by 5 units.