Step-by-step explanation:

Let the triplets' age be x, the sister's age is then x-5.
product of their age as given
xÂł.(x-5)=75749+x+x+x+x-5
x^4 - 5xÂł= 4x +75744
x^4 - 5xÂł -4x -75744=0
resolving the equation,
we get
x = 18
therefore, Age of ben,bob and bill is 18
so , age of stephanie is x-5 = 18-5 = 13
stephanie is 13 years old.
Answer: a=4
Step-by-step explanation:
6a+9=33
Subtract
6a=24
Divide
a=4
For perpendicular lines, m1m2 = -1 or m2 = -1/m1; where m1 and m2 are the slopes of the lines.
Here line 1 is 2x - y - 7 = 0
y = 2x - 7; Hence m1 = 2
m2 = -1/2
Required equation y - y1 = m2(x - x1)
y - (-1) = -1/2(x - 4)
y + 1 = -1/2x + 2
y = -1/2x + 2 - 1
y = -1/2x + 1