25% off means that they are paying 75% of the original price. Multiply d by 75%:
0.75d
Now you need to multiply the price by 1 plus the sales tax to get the total cost:
0.75d x 1.08
Simplify by multiplying 0.75 by 1.08 to get:
0.81d
The function f(x) = 5x² + 40x is a parabola. Then the vertex of the parabola will be at (–4, –80).
<h3>What is the parabola?</h3>
It is the locus of a point that moves so that it is always the same distance from a non-movable point and a given line. The non-movable point is called focus and the non-movable line is called the directrix.
The function f(x) = 5x² + 40x
Then add and subtract 80, then we have
f(x) = 5x² + 40x + 80 – 80
f(x) = 5(x² + 8x + 16) – 80
f(x) = 5(x + 4)² – 80
The vertex of the parabola will be at (–4, –80).
More about the parabola link is given below.
brainly.com/question/8495504
I = Prt
I=1020
r=0.12 (12% converted to decimal by dividing by 100)
t=5
1020=P(0.12)(5)
1020=P(0.6)
P=1700
So area is base x height:
5(x+2)=20
5x+10=20
5x=10
x=2
its A
