Answer: 46 years
Step-by-step explanation:
Let the father's age be x and the son's age be y, then 3 years ago:
Father = x - 3
son = y - 3
Then , from the first statement :
x - 3 = 3 ( y - 3 )
x - 3 = 3y - 9
x = 3y - 9 + 3
x = 3y - 6 .......................................... equation 1
In five years time
father = x + 5
son = y + 5
Then , from the second statement
x + 5 = 2 ( y + 5 )
x + 5 = 2y + 10
x = 2y + 10 - 5
x = 2y + 5 ........................ equation 2
Equating equation 1 and 2 , we have
3y -6 = 2y + 5
add 6 to both sides
3y = 2y + 5 + 6
subtract 2y from both sides
3y - 2y = 11
y = 11
substitute y = 11 into equation 1 to find the value of x
x = 3y - 6
x = 3(11) - 6
x = 33 - 6
x = 27
This means that the father is presently 27 years and the son is presently 11 years.
In four years time
father = 27 + 4 = 31
son = 11 + 4 = 15
sum of their ages in four years time will be
31 + 15 = 46 years
Answer:
$69
Step-by-step explanation:
80 x 75% (0.75) = 60
60 x 15% (0.15) = 9
60 + 9 = $69
7.779955 × 10 to the 4th power.
Answer:
B
Step-by-step explanation:
Use the pythagorean theorem
a² + b² = c²
a² + 63² = 65²
a² + 3969 = 4225
a² = 256
a = 16
x = 16 meters
Answer:
-103
243
Step-by-step explanation:
(q•r)(5) = q(r(5))
r(5) = 2(5²) + 1 = 51
q(51) = -2(51) - 1 = -103
(r•q)(5) = r(q(5))
q(5) = -2(5) - 1 = -11
r(-11) = 2(-11)² + 1 = 243