Please help this ones pretty easy just not sure how to do it

Mathematics

1 answer:

BARSIC [14]3 years ago

3 0

Answer:

-8i + 51

Step-by-step explanation:

(3+5i)(2-9i)

6+10i-18i-45i²

**i² = -1.

6-8i + -45(-1)

= -8i + 51

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ch4aika [34]

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3 years ago

PLEASE!!!!!!!The adjoining figure shows two circles with the same center. The

Nookie1986 [14]

<h3>Answer:</h3>

$\boxed{\boxed{\pink{\sf \leadsto Hence \ the \ area \ of \ shaded \ region \ is 264 cm^2}}}$

<h3>Step-by-step explanation:</h3>

Here , two circles are given which are concentric. The radius of larger circle is 10cm and that of smaller circle is 4cm . And we need to find thelarea of shaded region.

From the figure it's clear that the area of shaded region will be the difference of areas of two circles.

Let the,

Radius of smaller circle be r .
Radius of smaller circle be r .
Area of shaded region be $\bf Area_{shaded}$

$\bf \implies Area_{Shaded}= Area_{bigger}-Area_{smaller} \\\\\bf\implies Area_{Shaded} = \pi R^2 - \pi r^2 \\\\\bf\implies Area_{shaded} = \pi ( R^2-r^2) \\\\\bf\implies Area_{shaded} = \pi [ (10cm)^2 - (4cm)^2] \\\\\bf\implies Area_{shaded} = \pi [ 100cm^2-16cm^2] \\\\\bf\implies Area_{shaded} = \pi \times 84cm^2 \\\\\bf\implies Area_{shaded} = \dfrac{22}{7}\times 84cm^2 \\\\\bf\implies \boxed{\red{\bf Area_{shaded} = 264 cm^2 }}$