2x + 1.5x +20 = 90
3.5 x = 90-20
3.5 x = 70
x = 70/3.5
x = 20
angle DAE = 2*20 = 40
angle CAD = 1.5*20 +20 = 50
To find the y intercept you must substitute 0 into x.
F(x) = (-3x0) - (6x0) - 5
F(x) = -5
To find the axis of symmetry and vertex we use the formula -b/2a to find the x coordinate
x = 6/(-3x2)
x = 6/-6
x = -1
Now we need to find the y coordinate so we sub -1 into x.
F(x) = (-3x-1) - (6x-1) - 5
F(x) = 3 + 6 - 5
F(x) = 4
The axis of symmetry and vertex are (-1,4) and the y coordinate is -5. Hope this helps.
Simple interest,
FV=P(1+ni)
FV=future value=2500
P=present value, invested amount
n=number of years, =3
i=annual interest rate, =0.095
2500=P(1+3(0.095))
Solve for P.