Bosco

A boy scout troop is selling Christmas trees at a local tree lot.     

In the morning, they sold 4 Douglas Fir trees and 15 Noble Fir trees, earning a total of $862.     

In the afternoon, they sold 4 Douglas Fir trees and 23 Noble Fir trees, earning a total of $1,262.     

How much does each type of tree cost?      

                                 4D + 23N  =  1,262     

                                 4D + 15N  =     862     

subtract                               8N  =     400     

                                              N  =       50   —>  price of 1 Noble Fir     

                                 4D + 23N  =  1,262     

                                 4D + (23)(50)  =  1,262     

                                 4D                   =  1,262 – 1,150     

                                 4D                   =  112     

                                   D                   =    28   —>  price of 1 Douglas Fir     

check answer     

                    Does       (4)(28) + (15)(50)  =  862 ?     

                                     112     +     750     =  862 ?     

                                                       862     =  862  True     

_.     

  How much it's 2.13604289e-9     

  it's 0.00000000213604289     

  In scientific notation, e –9 means move     

  the decimal point nine places to the left.     

_.     

Tell whether the triangle with each set of side lengths is a right triangle.     

(1.)  0.9, 1.2, 1.5       (2.) 3.1, 5.7, 7.1       (3.)1, 2.4, 2.6      

(1)  Does (0.9)² + (1.2)²  =  (1.5)² ?     

                 0.81  +  1.44   =   2.25  ?   Yes     

(2)  Does (3.1)² + (5.7)²  =  (7.1)²  ?     

                9.61  +  32.49  =  50.41  ?   No     

(3)  Does (1.0)² + (2.4)²  =  (2.6)²  ?     

                 1.00  +  5.76   =  6.76    ?   Yes     

_.     

Translate the difference of five squared and n into symbols.     

A. 5^2 ÷ n     

B. 5^2x n     

C. 5^2- n     

D. 5^2+ n     

The answer is C. 5² – n     

^.     

the question was: 58,511 / 21 = 2,786 R? the calculator's answer was: 2.786238095238052 I have no idea if that's correct or nonsense     

Did you notice that 58,511 / 21 is   2786.238095238052     

and what you saw was                   2.786238095238052     

which are the same thing, just with the decimal point in a different place.     

Did you see something on the right of the display that looked like E3 or similar?     

That's scientific notation.  The "E3" means move the decimal point three places to the right.     

_.     

All the sides of a triangle have integer length.  One of the sides has length $28$.  What is the smallest possible perimeter of the triangle?     

By the Triangle Inequality Theorem,     

the smallest sum of the other two sides has to be more than 28.  But the sum cannot be 29     

because then they wouldn't be integers.  So the smallest sum of the other sides must be 30.     

So that makes 28 + 30 = 58 the smallest possible perimeter of the triangle.     

_.