It is 3y because of the calculation being equivalent
Answer:
t= <u>r-21</u>
7
Step-by-step explanation:
r = 7(t+3)
expanding the bracket
r = 7t + 21
bringing t to the left hand side
7t = r - 21
divide both sides by seven
t= <u>r-21</u>
7
Answer:

Step-by-step explanation:
Let sides of the triangle be 

Semi-perimeter (s) = 

Area of one tile 

So,
Area of 20 tiles 
Cost of polishing the floor at the rate of 2 rupees per sq.cm = 
If you multiplied the base times the width times the height you would get a final answer of 60m.