Answer:
Step-by-step explanation:
D(15) = 3500 -20(15)
D(15) = 3500 - 300
D(15) = 3200
In 15 hours of driving the Brown family is 3200(no unit given) away from home.
The area of the triangle will then be 9 times as great.
The formula of the area of a triangle is 1/2bh, so if the base has been tripled and the height has been tripled, you're essentially multiplying 3 to the original equation twice (3 x 3 = 9).
I believe (3*8)*6=3*(8*6) illustrates the associative property of multiplication.
(3*8)*6=3*(8*6)
24*6=3*48
144=144
(x+2) + 3(x+2)
x+2+3x+6
.. ( collect like terms )
= 4x+2+6
= 4x + 8 is your answer