Answer:
(5y-6)^2
Step-by-step explanation:
Note that the polynomial 25y^
2 −60y+36 is a perfect square trinomial, so we will use the following formula.
A ^2
−2AB+B^2
=(A−B) ^2
In this example we have A=5y and B=6 so,
25y^2
−60y+36=(5y−6)^2
Answer:
π·r^3 + 7·π·r^2 = r^2·π·(r + 7)
r + 7 is the height of the cylinder.
There are 17 possible choices for the first ball, 16 possible choices for the second and so on.. until 6 balls are chosen. Multiply the number of choices together.
17×16×15×14×13×12 = 8,910,720
This is also what's called a permutation, 17 choose 6
In permutations order matters so (1,2,3) is not the same as (3,2,1).
In this case using the elimination method is actually easier, but the question asks you to use substitution method so....
2x+y= -10
3x-y=0
1st equation: It is better to isolate 2x on both sides because the y is going to be positive no matter what, 2x+y=-10 => y=-2x-10
If you isolated 3x for the 2nd equation, the y will be negative, and you have to divide the whole equation by -1 to make it positive
Now we got y=-2x-10, lets substitute it in the 2nd equation and solve for x:
3x-(-2x-10) = 0
5x+10=0
5x=-10
x=-2
Now lets solve for y:
3(-2)-y=0
-6-y=0
y=-6
Lets see if the same is applicable for 1st equation
2(-2)+(-6)=-10
-10=-10
Yess!!
(-2,-6) is the solution
The answer to the question is explained at the beginning
Hope it helps!