# Algebra

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A brick staircase has a total of 16 steps The bottom step requires 112 bricks. Each successive step requires 4 fewer bricks than the prior one. How many bricks are required to build the staircase?

• Algebra -

you are finding the sum of 16 terms of an arithmetic sequence where
a = 112
d = -4
n = 16

S16 = (16/2)[2(16) + 15(-4) ]
= .....

• Algebra -

-224

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