Answer:
The son is 20
The man is 60
Step-by-step explanation:
We can set up this equation with what we know. Let <em>m</em> stand for the Man's current age, and let <em>s</em> stand for his son's current age.
We know the Man's current age is three times that of his son, so this equation can be written as: <em>m = 3s</em>
Ten years ago means the man's current age <em>minus</em> 10 years. So it is <em>m-10</em>. So ten years ago he was 5 times his son's age 10 years ago, <em>5(s-10)</em>
This can be written as: <em>m-10=5(s-10)</em>
Solve with either substitution or elimination, the choice is yours, it doesn't really matter which method you use. I'll be using substitution.
<em>m-10=5(s-10)</em>
<em>3s-10= 5s-50</em>
<em>40=2s</em>
<em>20 = s</em>
The son is <em>20</em> years old.
We know the man is currently 3 times his son's age, because <em>m=3s</em>, so just solve for m since you now know the value of <em>s.</em>
<em>m=3s</em>
<em>m=3(20)</em>
<em>m=60</em>
The man is <em>60</em> years old
1000m equals 1km so 600m equals 0.6km.
Answer:
370
Step-by-step explanation:
a=3 or 7
b=7 or 3
3³+7³=370
So than you check this graph so you see that the radius has a length of 4 units
from what result that thet x^2 +y^2 =4
so the choice 3rd is right sure
<span>We can safely assume that 1212 is a misprint and the number of seats in a row exceeds the number of rows by 12.
Let r = # of rows and s = # of seats in a row.
Then, the total # of seats is T = r x s = r x ( r + 12), since s is 12 more than the # of rows.
Then
r x (r + 12) = 1564
or
r**2 + 12*r - 1564 = 0, which is a quadratic equation.
The general solution of a quadratic equation is:
x = (-b +or- square-root( b**2 - 4ac))/2a
In our case, a = 1, b = +12 and c = -1564, so
x = (-12 +or- square-root( 12*12 - 4*1*(-1564) ) ) / 2*1
= (-12 +or- square-root( 144 + 6256 ) ) / 2
= (-12 +or- square-root( 6400 ) ) / 2
= (-12 +or- 80) / 2
= 34 or - 46
We ignore -46 since negative rows are not possible, and have:
rows = 34
and
seats per row = 34 + 12 = 46
as a check 34 x 46 = 1564 = total seats</span>
