Answer:
Present age
Son: 15
Father: 45
Step-by-step explanation:
Remark
Thank you for the translation. Without it, the problem would be impossible -- at least for me.
Givens
Let the present age of the father = x
Let the present age of the son = y
Solution
x + y = 60
How many years will pass? You could say it's z.
x + z = y When z years pass, the son will be his father's present age.
x + z + y + z = 120 when z is added to both their current ages, the result is 120 Collect like terms
x + y + 2z = 120
<u>x + y = 60 </u> Subtract The very first equation
2z = 60 Divide by 2
z = 60/2 30 years have passed.
z = 30
x + z = y
x + 30 = y Substitute x + 30 for the present y value (the father).
x + x + 30 = 60
2x = 30
x = 15
x + y = 60
15 + y = 60
y = 60 - 15
y = 45
So the son's age right now is 15
The father's age right now is 45
Answer:
d. 8
Step-by-step explanation:
Given: -3x + 2y = 1 and x = 5
Now plug x =5 in the given equation and find the value of y.
-3(5) + 2y = 1
-15 + 2y = 1
2y = 1 + 15
2y = 16
Dividing both sides by 2, we get
y = 8
Thank you.
Answer/Step-by-step explanation:
3. By substitution method, let's substitute
for y in the first equation.
Thus,
Solve for x

Add 4 to both sides




Multiply both sides by 3


Divide both sides by 5

Now, substitute 3 for x in the equation.




The solution of the equation is x = 3, y = -2
4. Solving by elimination, let's try to eliminate the x-variable by adding both equation together.


=> 
Divide both sides by -3 to solve for y


Substitute -5 for y in the first equation to find x


Subtract 10 from both sides


Divide both sides by 3


The solution is 
Answer:
c) 255
Step-by-step explanation:
d isn't divisible by 5 and both a and b aren't divisible by 3