A submarine travels 5.5 km due East from its base and then turns and travels due North for 3.4 km. How far away is the submarine from its base?
Give your answer rounded to 1 DP.​

6.5km

Step-by-step explanation:

If you make a diagram, you'll see the submarine forms a right angle triangle with the base, where the hypotenuse is the length from the submarine to its base, and 5.5 and 3.4 are the side lengths. To find the hypotenuse, use the formula a^2+b^2=c^2.

5.5^2+3.4^=c^2

41.81=c^2

6.466=c

Round it to one decimal point and you get 6.5km.

6.5km

Step-by-step explanation:

I think is this I am not really sure

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".