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3 years ago

Evaluate 2x2 - 1 when x = 3.

Mathematics

2 answers:

Alla [95]3 years ago

6 0

Answer:11

Step-by-step explanation:2(3)x2-1=11

Charra [1.4K]3 years ago

4 0

Hello!

2.x^2 - 1 = 2.3^2 - 1 = 2.9 - 1 = 18-1 = 17

Good luck!

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What are the correct answers and why? Simple and concise explanation please!!!

dezoksy [38]

Answer:

$\large\boxed{-\bigg[(x-3)^2+2x\bigg]+1}\\\\\boxed{-x^2+4x-8}$

Step-by-step explanation:

$(g\ \circ\ f)(x)=g\bigg(f(x)\bigg)$

$f(x)=(x-3)^2+2x\\\\g(x)=-x+1\\\\g\ \circ\ f\to\text{put f(x) instead of x in the function g(x)}:\\\\(g\ \circ\ f)(x)=-\bigg[\underbrace{(x-3)^2+2x}_{x}\bigg]+1$

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$-\bigg[(x-3)^2+2x\bigg]+1=-(x-3)^2-2x+1\\\\\text{use}\ (a-b)^2=a^2-2ab+b^2\\\\=-(x^2-(2)(x)(3)+3^2)-2x+1=-(x^2-6x+9)-2x+1\\\\=-x^2-(-6x)-9-2x+1=-x^2+6x-9-2x+1\\\\\text{combine like terms}\\\\=-x^2+(6x-2x)+(-9+1)=-x^2+4x-8$

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$-x^2+4x-8=-x^2+4x-2^2+2^2-8=-(x^2-4x+2^2)+4-8\\\\=-(\underbrace{x^2-(2)(x)(2)+2^2}_{(a-b)^2=a^2-2ab+b^2})-4=-(x-2)^2-4=-(x+1-3)^2-4$

$In\ (-x+1-3)^2+2x,\ x^2\ will\ be\ positive.\\In\ (-x+1-3)^2+2(-x+1),\ x^2\ will\ be\ positive.$

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3 years ago

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How do i solve <br> X^56 x X^14

sweet-ann [11.9K]

Answer:

x^70

Step-by-step explanation:

When multiplying exponents, you just add them up.

x^56+14= x^70

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3 years ago

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tensa zangetsu [6.8K]

6*6=36.....................

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2 wholes and 3/12 + 3/? = 2 wholes and 5/8 .what is the missing number ?

Sladkaya [172]

Basically you know that the 2 wholes from both sides cancel out.

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3/x = 5/8 - 3/12

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Simplify 9/24 and you will get 3/8

3/x = 3/8

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