Distribute on the left side
7.4a+22.2=3.2a+43.2
Subtract 3.2a from both sides
4.2a+22.2=43.2
Subtract 22.2 from both sides
4.2a=21
Divide both sides by 4.2
a=5
Step-by-step explanation:
x = father's age now
y = son's age now
x = 2y + 10
x - 20 = 5(y - 20) = 5y - 100
using the first in the second equation :
2y + 10 - 20 = 5y - 100
-10 = 3y - 100
90 = 3y
y = 30
x = 2y + 10 = 2×30 + 10 = 60 + 10 = 70
the father is now 70 years old, the son now 30 years old.
Current year is 2016
born year is 1977
old
2016 - 1977
39 years
Answer:
k=-1827/685
Step-by-step explanation:
8/9k+9/5=-4-9/7k
8/9k-(-9/7k)=-4-9/5
8/9k+9/7k=-20/5-9/5
56/63k+81/63k=-29/5
137/63k=-29/5
k=(-29/5)/(137/63)
k=(-29/5)(63/137)
k=-1827/685
|x|=absoulte value of x which means whatever x is, make it positive
so first solve any division/multiplication
the only one is 12/46=6/23
so we do the absoulte value signs
-3+45-(-14)
-(-14)=+14
-3+45+14=56
absoulute value of 56=56
56+(-|-87+6/23|)
-87+6/23=-86 and 17/23
absoulte value of -86 and 17/23=86 and 17/23
there is a negative sign in front of the absoulte vaulue so make it negative
56-86 and 17/23=-30 and 17/23 or about -30.73913