to inverse a equation make all y's x and andy x's y
Thus the inverse is
x=4y-8
Evaluated to
4y=x+8
y= \frac{1}{4}x +2
Not too sure if i can tell u much but the answer on my test is B
13. Pick a point and see which formula works.
Ay = -4, A'y = 7. Only the formula of selection D makes that translation.
14. Use the compound interest formula A = P*(1 +r/n)^(nt).
..1500*1.015^80 = 4935.99, matching selection C
15. The lid has a perimeter of 90", so the area of the sides is
.. 90" * 24" = 2160 in^2
The area of the lid is
.. 30" * 15" = 450 in^2
The gray area is (2160 -450) in^2 = 1710 in^2 larger, corresponding to selection C.
16. The only formula that maps (7, -1) to (21, -3) is that of selection D.
_____
The middle two problems are the only ones that require you to have prior knowledge. The others could be answered simply by seeing if the answers work.
