Plz help me with this

Mathematics

2 answers:

enyata [817]3 years ago

5 0

I’m pretty sure the answer is B.

pashok25 [27]3 years ago

5 0

Answer: $\bold{b)\quad \dfrac{-2\pm \sqrt{14}}{2}}$

<u>Step-by-step explanation:</u>

$2x^2+4x-5=0\qquad \implies\qquad a=2,\ b=4,\ c=-5\\\\\text{The quadratic equation is not factorable so use the Quadratic Formula:}\\x=\dfrac{-b\pm \sqrt{b^2-4ac}}{2a}\\\\\\x=\dfrac{-4\pm \sqrt{4^2-4(2)(-5)}}{2(2)}\\\\\\.\ =\dfrac{-4\pm \sqrt{16+40}}{4}\\\\\\.\ =\dfrac{-4\pm \sqrt{56}}{4}\\\\\\.\ =\dfrac{-4\pm 2\sqrt{14}}{4}\\\\\\.\ =\large\boxed{\dfrac{-2\pm \sqrt{14}}{2}}$

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1-116 1.2.6

ankoles [38]

Answer:

A. 30 adults; B. 24 not dolls

Step-by-step explanation:

$\begin{array}{rcl}\text{No. of adults} & = & \text{No. of visitors} \times \text{Fraction who are adults}\\& = & \text{100 visitors} \times \dfrac{\text{3 adults}}{\text{10 visitors}} \\& = & \textbf{30 adults}\\\end{array}$

If five-eighths of the prizes were dolls, then three-eighths of the prizes were not dolls.

$\begin{array}{rcl}\text{No. not dolls} & = & \text{No. of prizes} \times \text{Fraction not dolls}\\& = & \text{64 prizes} \times \dfrac{\text{3 not dolls}}{\text{8 prizes}} \\& = & \textbf{24 not dolls}\\\end{array}$