Answer:
A = 26
Step-by-step explanation:
sum of students = classA + classB + classC
let's say classA = A, classB = B, and classC = C
A + B + C = 66
class A has five more students than class B, so A = 5 more than B so A = 5+B
class C has 2 less students than class B, so C = 2 less than class B = B -2, so C = B-2
A + B + C = 66
A = 5+B
C = B-2
substitute 5+B for A and B-2 for C in the first equation to limit this to one variable (B)
(5+B) + B + (B-2) = 66
3B + 3 = 66
subtract 3 from both sides to isolate the variable and its coefficient
3B = 63
divide both sides by 3 to solve for B
B = 21
A = 5 + B = 5 + 21 = 26
The answer to that question is four
(x-h)^2=4P(y-k), vertex is (h,k)
P is distance from vertex to directix
remember to subtract P from the y value of the vertex (p-k) and that y value is the directix, y=p-k
nut
ok so one way is to just graph them on a graphing utility
remember if the graph opens up, then the directix is below that
or we can convert to 4P(y-k)=(x-h)^2 form where P is distance from directix
I will only convert the 1st one fully, you should be able to do the rest
1. y=-x^2+3x+8
multiply both sides by -1 since we don't like the x^2 term negative
-y=x^2-3x-8
add8 to both sides
-y+8=x^2-3x
take 1/2 of linear coeficient and square it and add to both sides
-3/2=-1.5
(-1.5)^2=2.25
-y+10.25=x^2-3x+2.25
factor perfect square
-y+10.25=(x-1.5)^2
force undistribute -1 in left side
(-1)(y-10.25)=something, we don't care anymore for now
factor out a 4 in -1
4(-1/4)(y-10.25)
k=10.25
p=-1/4=-0.25
directix=k-p=10.25-(-0.25)=10.5
directix is y=10.5
basically completee the square with x and find P by force factoring a 4 out
2. directix: y=-1.75
3. directix: y=1.5
4. directix: y=17.25
5. d: -37.5
6. d: 9.25
7. d=2.625
order them yourself
Answer:
option C
Step-by-step explanation:
Total number of items = 5
Number of items to choose = 2
Therefore, the number of combinations is
Answer:
c: -7
Step-by-step explanation:
