CPhill

Let N be the first number, N + 2 the second and N + 4 the third...

So we have

N + (N + 2 ) + (N + 4) = 187   combine like terms

3N + 6 = 187     subtract 6 from both sides

3N = 181      this doesn't have an integer answer, because 181 isn't divisible by 3

Thanx to the troll for spotting my  mistake...!!!

The weight of the box must be subtracted from the total....so we have

16c =  (212 - 20)

(34 x 16) + (11 x 19) + (1/2)(14 x 19)  ..... will give you your answer, Trincent...

Let the width = W

And the length is 20 more = W + 20

And area = W x L, so we have

W x (W + 20) = 525

W^2 + 20W = 525     subtract 525 from each side

W^2 + 20W - 525 = 0     factor

(W - 15) (W + 35)  = 0     and setting each factor to 0, we have that W = -35 or W = 15

Reject -35

So W = 15   .....and the length is 20 more  = 35

5.40 / 18

8.40 / 30

Compare these two things above.....whichever is less.....that's the better buy....

90^2 = 8100

100^2 = 10000

And since  8464 lies between them....the square root has to be a number that lies between 90 and 100 and also ends with either a 2 or an 8. This last digit squared would end in a four......no other numbers between 90 and 100 would have an ending digit of 4 when squared.

5.6*10^12/7*10^6     so we have

(5.6/7)  * (10^12/ 10 ^6)  =

.8 x 10^6  =

8 x 10^5

Thanks, Alan....I always forget that we can use Euler's "formula" on these...!!!

-5 + 6x - x^2 =

-5 - (x^2 - 6x )          complete the square on x...take one-half the coefficient on x

(= 3), square it (= 9)....then......add and subtract it...so we have...

-5 - (x^2 - 6x + 9 - 9) =

-5 + 9 - (x^2 - 6x + 9)       factor  the expression on the parenthesis

4 - (x - 3)^2

And that's it...