21X+7=2...........`\21X=2-7...........\ 21X=-5.............. X=-5÷21... this is the right answer..(x=-5÷21)
The general form of a quadratic equation is that which is expressed in a form,
ax² + bx + c = 0
To write the equation in its general form, eliminate the decimal by multiplying the equation by 10. It now becomes,
3x² + 50x - 70 = 0
The value of b is therefore 50 and the answer is the second choice.
Answer:
what's the question? I don't see anything
Answer: The average age is 7.1 years.
This problem is an example of when we need to take a weighted average. We simply can't just find the average of 5 and 8, because there are different children of each each.
To start, lets multiply the total number of children by their individual ages.
6 x 5 = 30 years
14 x 8 = 112 years
There are 142 years among the 20 years, so divide 142 by 20. This gives us an average age of 7.1 years.
If you could elaborate on what this is, I would be gladly to assist you, but there is uncertainty going on here. I apologise.