Corresponding measures have the same ratio.
.. (x -1)/4 = (2x +1)/10
.. 5(x -1) = 2(2x +1) . . . . . . multiply by 20
.. 5x -5 = 4x +2 . . . . . . . . eliminate parentheses
.. x = 7 . . . . . . . . . . . . . . . add 5 -4x
x = 7
If you had one row, you would have 22 chairs.
If you had two rows, you would have 22+22=44 chairs.
If you had three rows, you would have 22+22+22 chairs, or 66 chairs.
See the pattern?
If you had 40 rows, you would add 22 40 times, or 22*40=880 chairs.
Hope this helps!
Remember that 45%=45/100=0.45
So if the tennis player serves the ball 300 times, and 45% cannot be returned, then we can use the following expression to solve for the answer:
300*0.45=135serves
Answer: 135 serves will not be returned
