Math
posted by Ron on .
Can you please check my answers, thank you
#2.
5/y+4 + 11/y^2=y12 = 7/y3
Answer 2
#4
The length of a rectangle is 2 cm more than twice its width. If the perimeter of the rectangle is 40 cm, find the length of the rectangle.
A. 6 cm
B. 9 cm
C. 11 cm
D. 14 cm
Answer B = 9cm
#7
One computer printer can print a company's mailing labels in 40 minutes. A second printer would take 60 minutes to print the labels. How long would it take the two printers, operating together, to print the labels?
A. 30 minutes
B. 24 minutes
C. 50 minutes
D. 32 minutes
answer: B 24 minutes
#16.
Solve. Write the solution in interval notation.
x + 4 6
answer: (10,2)

#4 should be A) 6 cm.

#2
I have a strong feeling your equation was meant to say
5/(y+4) + 11/(y^2 + y  12) = 7/(y3)
because of the proximity of the + and = signs, also since y^2 + y  12 = (y+4)(y3)
so multiply each term by y^2 + y  12
5(y3) + 11 = 7(y+4)
5y  15 + 11 = 7y + 28
2y = 32
y = 16
#4
width  x
length  2x+2
2(2x+2 + x) = 40
6x + 4 = 40
6x = 36
x = 6
so the length is 2(6) + 2 = 14
#7
correct
#16
You left out the operation sign, I will assume it is >
x+4 > 6
x+4>6 or x4 >6
x>2 or x > 10
x> 2 or x < 10
if the statement was x+4 < 6
we would have
10 < x < 2
call me oldfashioned but my notation is more indicative than the "interval" notation that seems to be used quite often these days.