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One model of a portable keyboard, Model A, has a total of 61 black and white keys. It has five full octaves with 5 black keys in each octave. The Model B portable keyboard has 76 black and white keys. It has six full octaves with 5 black keys in each octave and one extra black key.

Find the number of white keys on the Model A keyboard.

Find the number of white keys on the Model B keyboard.

water molecules will move from the side of higher water concentration to the side of lower concentration until both solutions are isotonic. at this point, equilibrium is reached. in an isotonic solution, the flow of water in and out of the cell is happening at the same rate.

hope this < 3

for b its (t) and c its (d)

step-by-step explanation:

the answer is d

step-by-step explanation:

y+3=-4(x-2)

y+3=-4x+8

  -3         -3  

y=-4x+5

answer: (c) m∠qpo + (2x + 16)° = 180°

step-by-step explanation:

the opposite angles of a quadrilateral are supplementary.

so, ∠o + ∠q = 180°   and   ∠p + ∠r = 180°

since ∠r = 2x + 16°, we can use substitution as follows:

∠p + ∠r = 180°

∠p + (2x + 16)° = 180°