Alan

Replace the x's in f(x) with the arguments given; so, for example:

f(2) = -3 - 2 + (2*2)*(2*2), which simplifies to: f(2) = 11

With the other two, you will still be left with an algebraic expression as neither the numerical value of k, nor the form of function g is supplied.  That is you just have to replace x by k+1, and x by g(2). 

.

You probably take the ratio of the two MADs, so either 1.2/0.4 or 0.4/1.2 depending on which applies to seventh graders and which to sixth graders, which you don't specify!

.

1 mm is 0.1 cm so 70 mm = 7 cm and 80 mm = 8 cm.

VS = pi*7²*8 cm³ = 392*pi cm³

.

Use ncr(20,3) on the calculator on the home page here.

.

The discount is asked for as a percentage of the normal price, not of the number of erasers!

.

Good thinking civonamzuk!

.

Take log₁₀ of both sides to get

-3 + x = log₁₀(300)

-3 + x = log₁₀(3) + log₁₀(100)

-3 + x = log₁₀(3) + 2

x = log₁₀(3) + 5

.

(a) and (b) are correct.

For (c), if the "normal" price is that of 10 individual erasers (namely, $9) then the discount ($1) as a percentage  of the normal price is given by (1/9)*100, or ≈ 11%

.

The calculator here doesn't deal directly with gradians, only radians and degrees.  Since 100 gradians = 90 degrees you could do the calculation in degrees by converting from one to the other.

.