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{-b+\sqrt{D}}{2a} \ ; \ \dfrac{-b-\sqrt{D}}{2a}](https://tex.z-dn.net/?f=%5Cdfrac%7B-b%2B%5Csqrt%7BD%7D%7D%7B2a%7D%20%5C%20%3B%20%5C%20%20%20%5Cdfrac%7B-b-%5Csqrt%7BD%7D%7D%7B2a%7D)
![=\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)
Answer:
x=0.69897009
Step-by-step explanation:
expand by logarithms
10^x=5
=log(10^x)=log(5)
=x log(10)=log (5)
log base 10 of 10 is 1
x.l =log(5)
multiple bothside by 1
x=log(5)
x=0.6989709
Answer:
W = (1/7) t
Step-by-step explanation:
At t = 0, W = 0
At t = 56 minutes , W = 8 inches
W = k*t The y intercept = 0 because t = 0 W = 0
8 inches = k * 56 minutes
k = 8 / 56
k = 1/7 inches / minute
W = (1/7) t
Answer:
122 km/h
138 km/h
Step-by-step explanation:
distance = speed * time
One bus travels 16 km/h slower than the other
(s * 2) + (s - 16)2 = 520
2s + 2s - 32 = 520
4s = 552
s = 552/4
s = 138 km/h
s - 16 = 122 km/h