Answer:
49/8 is the value of k
Step-by-step explanation:
We have the system
x = -2y^2 - 3y + 5
x=k
We want to find k such that the system intersects once.
If we substitute the second into the first giving us k=-2y^2-3y+5 we should see we have a quadratic equation in terms of variable y.
This equation has one solution when it's discriminant is 0.
Let's first rewrite the equation in standard form.
Subtracting k on both sides gives
0=-2y^2-3y+5-k
The discriminant can be found by evaluating
b^2-4ac.
Upon comparing 0=-2y^2-3y+5-k to 0=ax^2+bx+c, we see that
a=-2, b=-3, and c=5-k.
So we want to solve the following equation for k:
(-3)^2-4(-2)(5-k)=0
9+8(5-k)=0
Distribute:
9+40-8k=0
49-8k=0
Add 8k on both sides:
49=8k
Divide both sides by 8"
49/8=k
Y=kx
-5=k(15)
-5/15=k
-1/3=k
now,
y=-1/5x
3=-1/5x
3×5=-1(x)
15=-1(x)
multiplying both sides by -1,we get
-15=x
Answer:
37 hours and 12 minutes
Step-by-step explanation:
six men completed a task in 24 hours and 48 minutes which means (24 x 60) + 48 = 1488 minutes
x is the number of minutes it would take 4 men to complete
6(1488) = 4x
8928 = 4x
x = 2232
x = 2220 + 12 or 37 hours and 12 minutes
6(4x + 5) = 3(x + 8) + 3
24x + 30 = 3x + 24 + 3
24x + 30 = 3x + 27
24x - 3x = 27 - 30
21x = - 3
x = -3/21
x = - 0.143 <==