Todd has 21 white tiles dnd some black tiles to make a mosaic. the mosaic has a total area of 144 square centimeters. each tile has an area of 3 square. how many black tiles did todd use?

the number of black tiles that Todd used is 27

Step-by-step explanation:

Let x represent the number of black tiles that Todd used.

Todd has 21 white tiles and some black tiles to make a mosaic. Each tile has an area of 3 square. It means that the total area of the white tiles is 21 × 3 = 63 cm^2

The total area of the white tiles is x × 3 = 3x cm^2

The mosaic has a total area of 144 Square centimeters. It means that

3x + 63 = 144

3x = 144 - 63 = 81

x = 81/3 = 27

i think it would be 43 movies that would have to be watched.

step-by-step explanation:

think about it. for the second plan, every month is 8 dollars. 8 x 12= 96. so thats the number for the second plan. now for the first plan, its annual meaning you have to pay 10 dollars every year. so now you have to get an equivalent amount of 86 since 96-10=86. 86 divided by 2 since every movie costs 2$ then you would have to watch 43 movies a year to get the same as the second plan. i really hoped this . have a wonderful day as well!