Answer:
x+2y=12-------(1)
x-2y=3---------(2)
Adding equations 1 and 2
we get
2x=18
x=9
Equation 1
9+2y=15
2y=15-9
2y=6
y=3
The solution of the given system is x=9, y=3
Step-by-step explanation
Answer:
John is 17,
Susan is 14,
and Khalid is 9.
Step-by-step explanation:
a = John's age
b = Susan's age
c = Khalid's age
Let's set our rules from the given information.
a = b + 3
c = b - 5
a + b + c = 40
Now, we can solve for b through substitution.
(b + 3) + b + (b - 5) = 40
3b - 2 = 40
3b = 42
b = 14
So, now that we have Susan's age, we can follow the rules and see if it holds.
17 + 14 + 9 = 40 Viola!
Answer:
x = -2
Step-by-step explanation:
<u><em>First, you need to subtract 8x from both sides:</em></u>
8x – 4 = 13x + 6
-8x -8x
____________
-4 = 5x + 6
<em><u>Then, subtract 6 from both sides:</u></em>
-4 = 5x + 6
-6 - 6
________
-10 = 5x
<u><em>Lastly, divide both sides by 5:</em></u>
-10 = 5x
-2 = x
1) in one minute for first wiil be 1/20
the other 1/30, it means that A paint in one minute 1/20 and B 1/30 then A+B in one minute 1/20 + 1/30 = 3+2/60 = 5 / 60, 5/60 = 1/12
if in one min they make 1/12 then in 12 min they paint all the wall
Answer:
Step-by-step explanation:
Volumes of two spheres A and B = 648 cm³ and 1029 cm³
Things to remember:
1). Scale factor of two objects = 
[
and 
are the radii of two circles]
2). Area scale factor = 
3). Volume scale factor = 
Volume scale factor Or Volume ratio = 
![\frac{r_1}{r_2}=\sqrt[3]{\frac{648}{1029} }](https://tex.z-dn.net/?f=%5Cfrac%7Br_1%7D%7Br_2%7D%3D%5Csqrt%5B3%5D%7B%5Cfrac%7B648%7D%7B1029%7D%20%7D)
![\frac{r_1}{r_2}=\frac{6(\sqrt[3]{3})}{7(\sqrt[3]{3})}](https://tex.z-dn.net/?f=%5Cfrac%7Br_1%7D%7Br_2%7D%3D%5Cfrac%7B6%28%5Csqrt%5B3%5D%7B3%7D%29%7D%7B7%28%5Csqrt%5B3%5D%7B3%7D%29%7D)
Therefore, scale factor =
≈ 6 : 7
Area scale factor Or area ratio = 
= 
≈ 36 : 49
Volume scale factor or Volume ratio = 
= 
≈ 216 : 343
