Answer:
120km
Step-by-step explanation:
10km in 15 min
3hrs = 3 x 60 min = 180 min
180min divided by 15min = 12
12 x 10km = 120 km
Answer:
$52.51
Step-by-step explanation:
16% of 45.27 is 7.24
45.27 + 7.24 is $52.51
Hope this helps!
Stay safe!!
Answer:
Step-by-step explanation:
-5x² - 6 = -4x
-5x² + 4x - 6 = 0
a = -5 ; b = 4 ; c = -6
Discriminant = b² - 4ac
= 4² - 4*(-5)*(-6)
= 16 - 120
= -104
roots = 
![=\dfrac{-4+\sqrt{-104}}{2*(-5)};\dfrac{-4-\sqrt{-104}}{2*(-5)}\\\\=\dfrac{-4+2i\sqrt{26}}{-10} ; \dfrac{-4-2i\sqrt{26}}{-10}\\\\=\dfrac{(-2)[2-i\sqrt{26}]}{-10} \ ; \ \dfrac{(-2)[2+i\sqrt{26}]}{-10}\\\\=\dfrac{2-i\sqrt{26}}{5} \ ; \ \dfrac{2+i\sqrt{26}}{5}](https://tex.z-dn.net/?f=%3D%5Cdfrac%7B-4%2B%5Csqrt%7B-104%7D%7D%7B2%2A%28-5%29%7D%3B%5Cdfrac%7B-4-%5Csqrt%7B-104%7D%7D%7B2%2A%28-5%29%7D%5C%5C%5C%5C%3D%5Cdfrac%7B-4%2B2i%5Csqrt%7B26%7D%7D%7B-10%7D%20%3B%20%5Cdfrac%7B-4-2i%5Csqrt%7B26%7D%7D%7B-10%7D%5C%5C%5C%5C%3D%5Cdfrac%7B%28-2%29%5B2-i%5Csqrt%7B26%7D%5D%7D%7B-10%7D%20%5C%20%3B%20%5C%20%5Cdfrac%7B%28-2%29%5B2%2Bi%5Csqrt%7B26%7D%5D%7D%7B-10%7D%5C%5C%5C%5C%3D%5Cdfrac%7B2-i%5Csqrt%7B26%7D%7D%7B5%7D%20%5C%20%3B%20%5C%20%5Cdfrac%7B2%2Bi%5Csqrt%7B26%7D%7D%7B5%7D)
Amy: x skirts
Betty: 2x skirts
Carol: (2x) + 7 skirts
If Amy has 18 less than Carol, than Carol's equation minus 18 equals Amy's equation:
[(2x) + 7] - 18 = x
+18 +18
(2x) + 7 = x + 18
- 7 -7
2x = x + 11
-x -x
x = 11
Input the solution for x into the girls equation to double check.
Amy: 11
Betty: 2(x)
2(11)
=22
Carol: (2x) + 7
22 + 7
=29
Does Amy have 18 less than Carol?
Carol - Amy = 18
29 - 11 = 18
18 = 18
the problem is solved
A pharmacist has 40% and 80% of iodine solutions on hand. How many liters of each iodine solution will be required to produce 4 liters of a 50% iodine mixture?
.
Let x = liters of 40% iodine
then
4-x = liters of 80% iodine
Using algebra:
.40x + .80(4-x) = .50(4)
.40x + 3.20-.80x = 2
3.20-.40x = 2
x = 4 liters (40% iodine)
80% iodine:
4-x = 4-4 = 0 liters needed (80% iodine)
