Question 152592
Ok, you got a good start!
Let b = number of boys yesterday and (b+4) = the number of boys today and g = number of girls (This didn't change).
Yesterday: g = 5b
Today: g = 3(b+4)
Since g = g, then;
5b = 3(b+4) Apply the distributive property on the right side.
5b = 3b+12 Subtract 3b from both sides.
2b = 12 Divide both sides by 2.
b = 6
So, yesterday, there were 6 boys plus 5*(6) girls for a total of 36 children.
Today, there are 6+4 = 10 boys and 3*10 = 30 girls for a total 40 children.