Not sure what the question is but 3x + 7 is the algebraic expression that would represent this statement.
D. take the number of dollars she has and multiply by .25.
dividing by a number is the same as multiplying by it's reciprocal. since she is dividing by .25, she needs to multiply by the reciprocal (4,) but instead, she is just multiplying by .25.
Equilateral
equi means equal
lateral means sides
all sides are equal
triangle has 3 sides
perimiter=side1+side2+side3
side1=side2=side3
area=1/2 times base times height
base=side
draw a line down the middle of te tiangle so you get 2 right triangles side by side
1/2base is one leg
base is hypotonuse
height is unknown
equilateral means that it is a 30-60-90 triangle with hypotonuse equal to 2x, height=x√3, bottom is x
1/2 times base times height=1959
1/2 times x times x√3=1959
multiply both sides by 2
(x^2)√3=3918
divide both sides by √3
x^2=3918/√3
square root both sides
x=47.5611
side=hypotonuse=2x
2x=2*47.5611
side=95.12222
legnth of each side is

cm or about 95.12222 cm
Since the square root of 13 is something really weird (3.6055 something) and does not have a clear end or repeats, it is irrational. Solve for the number before assuming anything
A. 1 out of 60 for the tv, 1 out of 25 for the video. This comes to 2/85 that one is faulty.
B. 286, since 285 has exactly a .95 chance