[I think you wrote the question wrong] -5 multiplied by -4 equals 20 and -5 and -4 equals -9
Option A
The simple interest earned over 6 years is $ 4050
<em><u>Solution:</u></em>
Martha invested a principal amount of $15,000 into a savings account that earns simple interest at a rate of 4.5% per year
<em><u>The formula for simple interest is given as:</u></em>

Where, "p" is the principal and "n" is the number of years and "r" is the rate of interest
From given,
p = 15000
r = 4.5 %
n = 6 years
<em><u>Substituting the values we get,</u></em>

Thus simple interest earned over 6 years is $ 4050
Convert to vertex form:-
= -0.04(x^2 + 39x)
= -0.04( (x + 19.5)^2 - 380.25)
vertex is at -0.04 * -380.25 = 15.21 yards
Maximum height is about 15.2 yards
Check the picture below.
so, notice, the composite is just a 4x6 rectangle, and a triangle whose base is 6 and altitude is 2. So, we can simply get the area of each figure and sum them up.
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