Answer: b. helium nucleus
Helium nucleus is the particle that is being emitted in an alpha radiation. This helium nucleus then transforms and becomes decays that are also known as alpha decays. The alpha particle maybe similar to helium nucleus however, it does not have electrons surrounding it.
X = -7
3 • 7 = 21
-3 • (-7) = 21
If you multiply two negative numbers you’ll end up with a positive. Thus, - 3 (-7) = 21.
he polynomial x(5x² + 10x + 15), it is not completely factored, 5x² + 10x + 15 can still be factored into two binomials.
<h3>
Polynomial</h3>
Polynomial is an expression that involves only the operations of <em>addition, subtraction, multiplication </em>of variables.
Given the polynomial x(5x²+10x+15), it is not completely factored, 5x²+10x+15 can still be factored,
Find out more on Polynomial at: brainly.com/question/2833285
Area=pir^2
diameter/2=radius
diameter=9
d/2=9/2=4.5=r
area=pi4.5^2
area=pi20.25
aproxpi=3.14
area=63.585
round hundreth
area=63.59
answer is 63.59cm^2