Answer:
6x + 13 = 12x - 20
Step-by-step explanation:
6x + 13 = 12x - 20
1)1.082*10^9
2)1.496*10^8
3)2.2794*10^8
4)7.784*10^5
5)1.4236*10^9
6)2.867*10^9
7)4.4884*10^9
Hope it helped!
So first create and define your variables:
Z = amount of zebra fish
N = amount of neon tetras
Now create your equations:
2z+2.15n=31.20
z+n=15
This is your system. There are multiple methods to use but in this problem I’ll use the substitution method by simplifying the bottom equation.
2z+2.15n=31.20
z=15-n
Now I’ll plug the bottom equation into the top one.
2(15-n)+2.15n=31.20
And just solve from here.
30-2n+2.15n=31.20
0.15n=1.20
n=8
So he bout 8 neon tetras, and 15-8= 7, so he bought 7 zebra fish
the value of x is 8 cm.
<u>Step-by-step explanation:</u>
Correct Question : In the diagram, the radius of the outer circle is 2x cm and the radius of the inside circle is 6 cm. The area of the shaded region is 220π cm2. What is the value of x? Enter your answer in the box.
We have ,
the area of a circle = πr²
the outer circle area =
the inside circle area =
According to Question,
the outer circle area - the inside circle area = he shaded region
⇒
⇒
⇒
⇒
Therefore , the value of x is 8 cm.