<span>[2(3+5)-2(4+1)]5
=</span><span>[2(8)-2(5)]5
=</span><span>[16-10]5
=6*5
=30</span>
Well since you're using 3/8 and you need to make 4 batches, you need to multiply 3/8 with 4 it would equal 12/8 or 1 4/8 (I could be wrong but this is my answer hopefully this helps) :) <span />
2 * 7 = 14 (the number of tiles for each row) 23 - 14 = 9 (the number of tiles subtracted from how many tiles that are taken away) 9 tiles are in the seventh row.
The trick is to exploit the difference of squares formula,

Set a = √8 and b = √6, so that a + b is the expression in the denominator. Multiply by its conjugate a - b:

Whatever you do to the denominator, you have to do to the numerator too. So

Expand the numerator:






So we have

But √12 = √(3•4) = 2√3, so
