Answer:
X=125/64
Step-by-step explanation:
x^2+4 x-5=0
x^2+4x=5
4x^3=5
x^3=5/4
x=5^3/4^3
x=125/64
The answer is D.
The others equal 90
Answer:
The correct answer is the number in the note is 80 and the first digit is 8.
Step-by-step explanation:
Dr. Green finds a note from another scientist. It says how many boxes of bug nets they should bring, but there is a smudge over the first digit of the number.
Number of nets that they must bring is 320.
Each box contains 4 nets.
There number of boxes necessary to be brought is given by
= 80.
Therefore the missing digit of number the number in the note is 8.
Answer:
13 l of 15%, 13 l of 25%, 26 l of 70%
Step-by-step explanation:
solutions:
final solution:
This includes 0.45*52l= 23.4 l acid
Let's assume:
- amount of 15% solution= x
- amount of 25% solution= y
- amount of 70% solution= z
- and we have z=2y
so there are 2 equation:
or
- x+y+2y= 52 ⇒ x+3y= 52 ⇒ x= 52- 3y
- 0.15x+1.65y=23.4
- 0.15*(52-3y)+1.65y=23.4
- 7.8-0.45y+1.65y=23.4
- 1.2y=23.4-7.8
- 1.2y= 15.6
--------
- x= 52- 3*13= 13 l
- z= 2y= 2*13= 26 l
5 would be the answer to it