Kristina, liz, and heather all made cookies. kristina made 2.4 dozen less than 6 times as many dozen as heather. liz made 1.8 dozen more than 5 times as many dozen as heather. if kristina and liz made the same number of cookies, how many dozen cookies did heather make?

Based on the number of cookies each girl made and if Kristina and Liz made the same number of cookies, then Heather made 4.2 dozen cookies.

Step-by-step explanation:

In order to find the number of cookies that Heather made, you need to set up two equations that represent the number of cookies that Kristina and Liz each made.  Since Kristina made 2.4 dozen less than 6 times as many dozen as Heather, we can represent that with the equation  6c - 2.4.  Since Liz made 1.8 dozen more than 5 times as many dozen as Heather, we can represent that with the equation 5c + 1.8.  We can set both equations equal to each other since Liz and Kristina made the same number, so 6c - 2.4 = 5c + 1.8.  Solving for 'c', which represents how many dozen cookies Heather made, we get 4.2  

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.

step- i d k and i d c : )

you: : 0

bye