Batteries produced by a manufacturing company have had a life expectancy of 135 hours. because of an improved production process, the company believes that there has been an increase in the life expectancy of its batteries. a sample of 42 batteries showed an average life of 140 hours. from past information, the standard deviation of the population is known to be 24 hours. test to determine whether there has been an increase in the life expectancy of batteries. what is the test statistic, and what conclusion can be made at the .10 level of significance?

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

3x + 4y -25 =0 represents the amount of change sianna should recieve

ummm seems that u didnt post the attachement !

144.50

step-by-step explanation:

21.5 x 13.4=288.10 divide by 2