Given the diagram to the right, determine m

The measure of Angle S is 75 (degrees).

Step-by-step explanation:

Key skills needed to solve this are: Sums of a triangle, one variable equation, operations

1) All the angles in a triangle add up to equal 180 degrees.

2) We can use this to say that Angle S + Angle R + Angle T is 180 degrees.

3) Subsitute in the expression for each angle: 7x+40+8x+25+5x+15 = 180

4) Combine like terms

7x + 8x + 5x is 20x & 40 + 25 + 15 is 80

This means that 20x + 80 = 180

5) Move 80 to the right side: 20x = 100

6) Divide by 20 andbget x equal to 5

7) To find Angle S, you need to plug in 5 into the expression.

7x + 40 = 7(5) + 40 = 35 + 40 = 75 degrees

The measure of Angle S is 75

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".