A family goes to an amusement park adult tickets cost $21 children under 10 years of age pay $15 write an algebraic expression for the total cost then find the total cost of 4 adult tickets and 3 children's tickets

$129

Step-by-step explanation:

Let us represent:

Cost Adult tickets = x

Cost Children's tickets = y

The total cost of ticket = C =

A family goes to an amusement park adult tickets cost $21 children under 10 years of age pay $15

C = $21 × x + $15 × y

C = 21x + 15y

The total cost of 4 adult tickets and 3 children's tickets is calculated as:

C = 21 × 4 + 15 × 3

C = 84 + 45

C = $129

is there any attachment? what are the equations?

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.