Answer:
y = 0
x = -4
( x, y ) = ( -4 , 0 )
Step-by-step explanation:
y = 5x + 20
y = -2x - 8
Substitute
5x + 20 = -2x - 8
Add 8 on both sides
5x + 20 + 8 = -2x - 8 + 8
5x + 28 = -2x
Subtract 5x on both sides
5x - 5x + 28 = -2x - 5x
28 = -7x
Divide by -7 on both sides
28/-7 = -7x/-7
-4 = x
Now that you have x, you can substitute it in one of the equations that was given to find the value of y.
y = 5x + 20
y = 5(-4) + 20
y = -20 + 20
y = 0
Or....
y = -2x - 8
y = -2(-4) - 8
y = 8 - 8
y = 0
They will both be 0 no matter what
Point form = ( -4, 0 )
Hope this helped
Answer:
Step-by-step explanation:
c.
y= 30x² +44x +16
factor
y= 2 (15x² +22x +8)
find zeros
15x²+22x+8=0
ax²+bx+c=0
x= (-b±√(b²-4ac))/2a
x= -22±√484-480/30 = -22±2/30 = -11±1/15
there are 2 zeros x= -10/15 ; x= -12/15
d.
y= 10x² +60x +80
factor
y= 10(x²+6x+8) = 10( x+2)(x+4)
finding zeros
x+2 =0 so x= -2
x+4 =0 so x= -4
there are 2 zeros x= -2; x= -4
Answer:
6.66 hours, that is, 6 hours and 40 minutes.
Step-by-step explanation:
If Mike can plow a field in 12 hours, we plows 1/12 of the field each hour.
If Phil can plow a field in 15 hours, we plows 1/15 of the field each hour.
So if they are working together, they can plow (1/12) + (1/15) of the field each hour, that is:
(1/12) + (1/15) = (5 + 4) / 60 = 9 / 60 = 3 / 20 = 1 / 6.66
So if they work together, they can plow the field in 6.66 hours, that is, 6 hours and 40 minutes.
