Given:
f(x)=2x-1
g(x)=x+1
h(x)=2x^2+x-1

Step-by-step explanation:

(a)

f(-2)

2(-2)-1

-4-1

-5

(b)

h(3b)

2(3b)²+3b-1

2(9b²)+3b-1

18b²+3b-1

9

(c)

x+1 - 3(2x-1)-2(2x²+x-1)

x+1 - 6x+3-4x²-2x+2

-4x²-7x+6

(d)

(f-g)(-2)

2x-1-(x+1)

2x -1 - x - 1

x - 2

-2 - 2

-4

(e)

((2x²+x-1)(x+1))

2x³+2x²+x²+x-x-1

2x³+3x²-1

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.