Answer:
r=4
Step-by-step explanation:
Let's solve your equation step-by-step.
−4(r+2)=4(2−2r)
Step 1: Simplify both sides of the equation.
−4(r+2)=4(2−2r)
(−4)(r)+(−4)(2)=(4)(2)+(4)(−2r)(Distribute)
−4r+−8=8+−8r
−4r−8=−8r+8
Step 2: Add 8r to both sides.
−4r−8+8r=−8r+8+8r
4r−8=8
Step 3: Add 8 to both sides.
4r−8+8=8+8
4r=16
Step 4: Divide both sides by 4.
4r
4
=
16
4
r=4
Answer:
r=4
The answer is 11.25 mm.
A diameter of a circle is twice of its radius: d = 2r ⇒ r = d/2
small circle large circle
radius: r1 radius: r2 = ?
diameter: d1 = 15 mm
⇒ r1 = d1/2 = 15/2 mm
Since t<span>he ratio of the radii of two circles is 2:3, we have:
r1 : r2 = 2 : 3
which can also be expressed as:
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We know that r1 is 7.5, so let's implement it:
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Let's multiply both sides of the by 3r2:

⇒

⇒