Question

Evaluate the expression. 1/2 - 4 (1/2 + 1)^2

Answer 1

Answer:

D. -17/2

Step-by-step explanation:

1/2 - 4 (1/2 + 1)^2

First we evaluate what is inside the parentheses

1/2 - 4  (3/2) ^2

Now we square what is inside the parentheses

1/2 - 4(9/4)

Now multiply

1/2 -9

Get a common denominator  9 = 9 *2/2 = 18/2

1/2 - 18/2

-17/2

Answer 2

Use PEMDAS:

P Parentheses first

E Exponents (ie Powers and Square Roots, etc.)

MD Multiplication and Division (left-to-right)

AS Addition and Subtraction (left-to-right)

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$\dfrac{1}{2}-4\left(\dfrac{1}{2}+1\right)^2=\dfrac{1}{2}-4\left(1\dfrac{1}{2}\right)^2=\dfrac{1}{2}-4\left(\dfrac{1\cdot2+1}{2}\right)^2\\\\=\dfrac{1}{2}-4\left(\dfrac{3}{2}\right)^2=\dfrac{1}{2}-4\cdot\dfrac{3^2}{2^2}=\dfrac{1}{2}-4\cdot\dfrac{9}{4}=\dfrac{1}{2}-1\cdot\dfrac{9}{1}\\\\=\dfrac{1}{2}-9=\boxed{-8\dfrac{1}{2}=-\dfrac{8\cdot2+1}{2}=\boxed{-\dfrac{17}{2}}}\to\boxed{D.}$