70% of the people were adults
First you subtract 1500-450 = 1050
Then you divide 1050/1500 = .7
We need the following to be true
a+2b = -a
a+4 = 2a - 3b
Let's look at the first equation.
a + 2b = -a
Subtract both sides by a
2b = -2a
b = -a
Substitute b= -a into the second equation
a+4 = 2a + 3a
a + 4 = 5a
4a = 4
a = 1
Just take the negative of that and you get the value of b.
b = -1
Your solution is a=1 and b = -1.
Have an awesome day! :)
Answer:
If you are solving the equation for x :
3x + 3y = 180
3x = -3y + 180
x = -y + 60 or x = 60 - y
If you are solving the equation for y:
3x + 3y = 180
3y = -3x + 180
y = -x + 60 or y = 60 - x