Problema Solution

one number is eight more than a second number. Three times the first is 2 less than 4 times the second. what are the numbers

Answer provided by our tutors

Write your two equations from the information given:

n = the first number     and  y = the second number

Here are the two equations we need to solve to find our mystery numbers:

n = 8 + y

3n = 4y - 2

Think of it this way: We know what n equals, so substitute it in the second equation so that we only have to solve for y.

3(8 + y) = 4y - 2

We have to multiply 3 times each number in the parenthesis:

24 + 3y = 4y - 2

Now put like terms on opposite sides of the = sign. Remember to switch signs as they cross over...

24 + 2 = 4y - 3y     Now combine and solve for y...

26 = y

Now put y into the first equation to solve for n...

n = 8 + y

n = 8 + 26         

n = 34

Now work the second equation...

3(34) = 4(26) - 2

102 = 104 - 2

102 = 102      bingo!

So we know that our two numbers fit the criteria...

34 is 8 more than 26

and 3 times 34 is 2 less than 4 times 26