Solve 2x2 + 20x = −38.

1 answer:

4 0

2x^2+20x=-38 divide both sides by 2

x^2+10x=-19, halve the linear coefficient, square it, than add that value to both sides of the equation, in this case add (10/2)^2=25...

x^2+10x+25=6 now the left side is a perfect square

(x+5)^2=6 take the square root of both sides

x+5=±√6 subtract 5 from both sides

x=-5±√6 (so answer c.)

You might be interested in

If the silver accounts for 84% of the bar's weight, what is the weight of the silver?

lidiya [134]

Weight=8.15 ounces
silver=84%of the total weight
silver=(84/100)×8.15 ounces
silver= 0.84×8.15 ounces
silver=7.5795 ounces
silver=7.580 ounces (rounded to nearest thousandth)

8 0

2 years ago

Need to know the population in 2015

Margarita [4]

$\bf P=1110.9e^{kt}\quad 
\begin{cases}
P=1200 &\textit{in thousands}\\
t=2 &\textit{in 2002}
\end{cases}\implies 1200=1110.9e^{k2}
\\\\\\
\cfrac{1200}{1110.9}=e^{2k}\implies ln\left( \frac{1200}{1110.9} \right)=ln(e^{2k})\implies ln\left( \frac{1200}{1110.9} \right)=2k
\\\\\\
\cfrac{ln\left( \frac{1200}{1110.9} \right)}{2}=k\implies 0.0385755\approx k\implies 0.0386\approx k\\\\
-------------------------------\\\\$

$\bf P=1110.9e^{0.0386t}\qquad 
\begin{cases}
t=14\\
\textit{year 2015}
\end{cases}\implies P=1110.9e^{0.0386\cdot 14}
\\\\\\
P\approx 1907.0747\implies about\ 1,907,075\textit{ once rounded up}$

3 0

3 years ago

Complete the equation for this model.

Arturiano [62]

Answer:

(-18) + (-2) = -20

Step-by-step explanation:

arrow is moving from -18 to -20.

3 0

2 years ago

I need help with 4th grade math please show the problem and strategies thank you so much

irakobra [83]

70 palm trees are on that street

7 0

3 years ago

7. Find a conversion factor between cubic meters and cubic

RUDIKE [14]

Step-by-step explanation:

We know that,

1 m = 100 cm

the conversion from m² to cm² is as follows :

(1 m)² = (100 cm)² = 10000 cm²

A conversion factor between cubic meters and cubic centimeters is as follows :

(1 cm)³ = (100 cm)³

= 1000000 cm³

To convert m³ to cm³, multiply by 1000000.

Hence, this is the required solution.

3 0

3 years ago