Answer:
X=3, y=5
Step-by-step explanation:
3x + y = 14 equation 1
y=5 equation 2
3x + 5 = 14. substitute value of y from equation 2 into equation 1
3x=9
x-3
if the diameter is 15, its radius is half that, or 7.5
![\bf \textit{area of a circle}\\\\A=\pi r^2~~\begin{cases}r=radius\\[-0.5em]\hrulefill\\r=7.5\end{cases}\implies A=\pi 7.5^2\implies A=56.25\pi \\\\\\A\approx 176.71459\implies A = \stackrel{\textit{rounded up}}{177}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Barea%20of%20a%20circle%7D%5C%5C%5C%5CA%3D%5Cpi%20r%5E2~~%5Cbegin%7Bcases%7Dr%3Dradius%5C%5C%5B-0.5em%5D%5Chrulefill%5C%5Cr%3D7.5%5Cend%7Bcases%7D%5Cimplies%20A%3D%5Cpi%207.5%5E2%5Cimplies%20A%3D56.25%5Cpi%20%5C%5C%5C%5C%5C%5CA%5Capprox%20176.71459%5Cimplies%20A%20%3D%20%5Cstackrel%7B%5Ctextit%7Brounded%20up%7D%7D%7B177%7D)
J)x^2 +2x +yx+2y-5x-10
x^2-3x+yx-10
k)5y^2(1-2y)
l)a(x+y+z)
Answer:
B. 7x - 5
Explanation
Given the expression 21x^2 + 13x – 20, to get which of the given expression is a factor we will have to factorize the equation first as shown;
21x^2 + 13x – 20
= 21x^2 + 28x - 15x - 20
= 7x(3x+4) -5(3x+4)
= (7x-5)(3x+4)
Hence one of the factors is 7x - 5
