I am trying to figure out how to write the equation to solve: the first number is 5 less than the second number. Four times the first number plus 5 times the second number is 74. Find the numbers

Respuesta :

There are two numbers involved, let's call them x and y (x=first y=second).

Let's look at the information involved.
The first number is 5 less than the second.
So, X=Y-5.
Four times the first number plus 5 times the second number is 74.
So we can deal with just one variable, which will be Y, we can insert the expression y-5 for x.
So, the equation would look like:
4(y-5)+5Y=74
Let's solve.

We need to multiply the parenthesis first.
4y-20+5Y=74
Now add like terms.
9Y-20=74
We need Y by itself, so lets add 20 to both sides.
9Y=94
Let's divide.
10 4/9=Y
Since the first number is five less, it is 5 4/9. Let's check by putting it through the equation.
4(5 4/9)+5(10 4/9)=
21 7/9+52 2/9
73+1=74

So the numbers are 5 4/9 and 10 4/9.