Answer:
2x^2+4x-30=0
Step-by-step explanation:
2x^2+10x-6x-30=0
2x(x+5)-6(x+5)=0
(2x-6)(x+5)=0
2x-6=0 x+5=0
x=6/2 x=-5
x=3
Answer:
- 35 grams of 11.43% solution
Step-by-step explanation:
The end solution has same volume as initial volumes of mixture.
The concentration of solution is calculated as below
- 10*0.15 + 25*0.1 = 4 g
- 4 / 35*100% = 11.43% (rounded)
Answer:
The percent of error in her measurement is 1.3%
Step-by-step explanation:
we know that
The circumference of a circle is equal to

where
D is the diameter
we have

assume

substitute
----> This value represent the 100% (theoretical value)
Find the difference between the theoretical value and the measured value
Find the percentage by proportion

Answer:
Percentage loss of the number of trees is
.
Step-by-step explanation:
Given: After a storm,
trees out of
were left standing.
To find: What is the percentage loss of the number of trees?
Solution:
We have,
Total number of trees 
Number of trees left standing 
Therefore, loss of trees
We now that 



Hence, the percentage loss of the number of trees is
.