Answer is 76 - 2x
When solving these problems, you have to look at each individual word step by step
76 is being decreased
decreasing means something is being taken away from it, so this must be subtraction
76 -
by twice a number
so something is definitely being multiplied by 2
76-2
Now since we don't know this number that is being multiplied by 2 , you would have to put x in it's place.
76-2x
If they are 2.5 inches tall and the back splash is 2.5 feet tall that means you can fit 12 tiles vertically.
6 inches is 1/2 of a foot so 16 tiles can fit horizontally in 8 feet.
12 x 16 = 192
Final answer:
192 tiles
Hope I helped :)