Answer:
b
Step-by-step explanation:
Since the triangles are similar then the ratios of corresponding sides are equal, that is
=
, substitute values
=
( cross- multiply )
10(6x + 3) = 25(x + 11) ← distribute parenthesis on both sides
60x + 30 = 25x + 275 ( subtract 25x from both sides )
35x + 30 = 275 ( subtract 30 from both sides )
35x = 245 ( divide both sides by 35 )
x = 7
Then
KL = 6x + 3 = 6(7) + 3 = 42 + 3 = 45 → b
If the parabola has y = -4 at both x = 2 and x = 3, then since a parabola is symmetric, its axis of symmetry must be between x = 2 and x = 3, or at x = 5/2. Our general equation can then be:
y = a(x - 5/2)^2 + k
Substitute (1, -2): -2 = a(-3/2)^2 + k
-2 = 9a/4 + k
Substitute (2, -4): -4 = a(-1/2)^2 + k
-4 = a/4 + k
Subtracting: 2 = 2a, so a = 1. Substituting back gives k = -17/4.
So the equation is y = (x - 5/2)^2 - 17/4
Expanding: y = x^2 - 5x + 25/4 - 17/4
y = x^2 - 5x + 2 (This is the standard form.)
A
I believe that I am correct
-3√45 + 3√20 = -3√(9 · 5) + 3√(4 · 5) =
= -3√(3² · 5) + 3√(2² · 5) =
= -3 · 3√5 + 3 · 2√5 =
= -9√5 + 6√5 = -3√5 ← the end