Factor completely: 3x2 + 9x − 3

3x2 + 9x − 3 (a 3 can be divided from each number)
3(x2+3x-1)

can x2+3x-1 be factored out anymore? no

3(x2+3x-1) is the answer

7 0

4 years ago

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If f(a) = 2a ^ 3 + 3a ^ 2 + 5 , find f(- 2)

UkoKoshka [18]

<h2>Answer: 1</h2>

Step-by-step explanation:

Just plug in -2 anywhere you see an a

$f(a)=2a^3+3a^2+5\\f(-2)=2(-2)^3+3(-2)^2+5\\f(-2)=2(-8)+12+5\\f(-2)=-16+12+5\\f(-2)=1$

8 0

2 years ago

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Find all the missing elements:

pshichka [43]

Answer:

C = 21.78 and a= 8.88

Step-by-step explanation:

Here, sides b=7 and c=3

Also, Angle B=60

Angle B is between side c and a

It can be solve by cosine rule and sin rule

sin rule says,

$\frac{a}{sinA} = \frac{b}{sinB} = \frac{c}{sinC} \\ \frac{a}{sinA} = \frac{7}{sin60} = \frac{3}{sinC} \\ \frac{7}{sin60} = \frac{3}{sinC} \\ sinC = \frac{3}{7} \: sin60 = 0.3711537445 \\ \\ C = 21.78$

cosine rule says,

${a}^{2} = {b}^{2} + {c}^{2} + 2bc \: cos(B) \\ {a}^{2} = {7}^{2} + {3}^{2} + 2(7)(3) \: cos(60) \\ {a}^{2} = 49 + 9 + \:21 = 79 \\ a = 8.88$

7 0

3 years ago