Answer:
l
Step-by-step explanation:
Answer:
2x^2 = 6x - 5.
-x^2 - 10x = 34.
These have only complex roots/
Step-by-step explanation:
3x^2 - 5x = -8
3x^2 - 5x + 8 = 0
There are complex roots if the discriminant 9b^2 - 4ac) is negative.
Here the discriminant D = (-5)^2 - 4*-5*8 = 25 + 160
This is positive so the roots are real.
2x^2 = 6x - 5
2x^2 - 6x + 5 = 0
D = (-6)^2 - 4*2*5 = 36 - 40 = -4
So this has no real roots only complex ones.
12x = 9x^2 + 4
9x^2 - 12x + 4 = 0
D = (-12)^2 - 4*9 * 4 = 144 - 144 = 0.
- Real roots.
-x^2 - 10x = 34
x^2 + 10x + 34 = 0
D = (10)^2 - 4*1*34 = 100 - 136 = -36.
No real roots = only complex roots.
Answer:
4 hours, $60
Step-by-step explanation:
Assuming "d" is equal to the dollars Jacob earned and h= hours, you start by setting the equations equal to each other, since both are equal to "d."
15h=10h+20
Subtract 10h from both sides (to combine like terms) so the equation becomes:
5h=20
Divide 5 from both sides, to isolate "d" :
h=4
The number of hours Jacob worked is 4, as the equation above shows. To find the amount of money Jacob made, substitute 4 as "h" into the two original equations:
d= 15(4) d=$60
d=10(4)+20 d=$60
Jacob earned $60 dollars in 4 hours.
It takes Emily 6 minutes to wash the car. This means he washes 16
1
6
of the car per minute.Larissa therefore washes 18
1
8
of the car per minute. Working together, they both wash 16+18
1
6
+
1
8
of the car, or 724
7
24
of the car each minute. This means that it takes 247
24
7
minutes to wash the entire car — or 3 minutes, 25.714285... seconds total.
Answer:
$1.17
Step-by-step explanation:
$0.26*4.5= $1.17
