CPhill

7. (x + 3) (x -5)> = 0  (B)  is the correct answer

15.   x^2 + 5x <= 0    (C)   is correct 

I'm not sure what the question is......if we have  a parallel line with the same x intercept as the given line ........it will have the same equation as the given one.......

A cone has 1/3 the volume of its associated cylinder  [ a cylinder with the same height and radius]

Let the number of nickels = x    then.....the number of dimes = x + 8   and we have that.....

Number * quantity  = total value  ......so.....

.05x +  .10(x + 8)  = 3.05        multiply through by 100

5x  + 10(x + 8)  = 305    simplify

15x + 80   = 305      subtract 80 from both sides

15x = 225     divide both sides by 15

x = 15    =  the number  of nickels

x + 8   =  15 + 8 =  23   = number of dimes

Well done, guys......

[2/5]x+7=[1/4]x-[7/2]    multiply through by the common denominator of 2, 4, 5   = 20

8x  + 140  = 5x - 70   add 70 to both sides,     subtract 8x from both sides

210  = - 3x       divide both sides by -3

-70  = x

A_t = A₀ ( 1 + r)^t

A = 300(1.05)^5 = about $382.88

2x-3/4= x+8/9  add3/4 to both sides.........subtract x from both sides

x = 8/9 + 3/4         get a common denominator - 36 -on the right

x = 32/36 + 27/36

x = 59/36

(3/4)N = 64      multiply both sides by (4/3)

N = 64(4/3)  = 85 1/3

y/2 - y/3= -1          get a common denominator - 6- on the left side

[3y - 2y] / 6  = 1  simplify,  multiply both sides by 6

y  =  6

3(2x-4) =24      divide both sides by3

2x - 4   =  8      add 4 to both sides

2x  = 12            divide both sides by 2

x = 6