Chau rented a truck for one day. There was a base fee of $19.95, and there was an additional charge of 99 cents for each mile driven. Chau had to pay $157.56 when he returned the truck. For how many miles did he drive the truck?

139 miles

Step-by-step explanation:

1) find the equation:

157.56=19.95+0.99x

we are solving for x

2) subtract 19.95 from both sides:

157.56=19.95+0.99x

-19.95     -19.95

137.61=0.99x

3) we divide 0.99 from both sides:

137.61=0.99x

/0.99      /0.99

139=x

Chau drove 139 in the truck in total.

have a lovely day/night!

v: l•w•h÷2.

v: 20•6•8 ÷2

v: 960÷2

v: 480

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.