Answer:
x=6
Step-by-step explanation:
h(x) = -( x-2)^2 +16
We want when h(x) = 0
0 = -( x-2)^2 +16
Subtract 16 from each side
-16 = -( x-2)^2 +16-16
-16 = -( x-2)^2
Divide by -1
16= ( x-2)^2
Take the square root of each side
±sqrt(16) = sqrt(( x-2)^2 )
±4 = x-2
Add 2 to each sdie
2 ±4 = x-2+2
2+4 = x 2-4 =x
6 =x -2 =x
since time cannot be negative
x=6
We can let
a = 1/(x-1)
b = 1/(y+2)
and rewrite the equations as
2a - b = 10
a + 3b = -9
Using the first to write an expression for b, we get
b = 2a - 10
Substituting this into the second equation gives
a + 3(2a -10) = -9
7a -30 = -9 . . . . . . . . simplify
7a = 21 . . . . . . . . . . .add 30
a = 3
b = 2·3 - 10 = -4
Now, we can find x and y.
3 = 1/(x -1)
x - 1 = 1/3
x = 1 1/3 = 4/3
-4 = 1/(y +2)
y +2 = -1/4
y = -2 1/4 = -9/4
Then the desired sum is
x + y = 4/3 -9/4 = (16 -27)/12
x + y = -11/12
The appropriate choice is ..
c. -11/12
Answer:
(x, y) = (-3, -6)
Step-by-step explanation:
The second equation can be used to write an expression for y:
... -5x -21 = y . . . . . . . add y-21 to both sides
This expression can be substituted for y in the first equation:
... 6 = -4x +(-5x -21)
... 27 = -9x . . . . . add 21, collect terms
... -3 = x . . . . . . . divide by -9
Using this value of x in the expression for y, we find ...
... -5(-3) -21 = y = -6
The solution is x = -3, y = -6.
Answer:
Step-by-step explanation:
The number is 49, First do 21 / 3 to find what 1/7 of the number is. We get 7, so we know 1/7 is 7 so if we do 7 x 7 we will have 7/7 or one whole and 7x7 is 49. Hope this helps
