Mystery 2-digit numbers and systems of linear equations in three variables
There are three boxes to be added together to get 87.
The first box is ten more than the second and the
second is ten more than the third.
_ + _ + _ = 87
Let x be the first number
Let y be the second number
Let z be the third number
Then, we get the following 3 equations
x + y + z = 87 (1)
x = y + 10 (2)
y = z + 10 (3)
Using (3), we get z = y - 10
Substitute y - 10 for z and y + 10 for x in (1)
y + 10 + y + y - 10 = 87
3y = 87
y = 29
z = y - 10 = 29 - 10 = 19
x = y + 10 = 29 + 10 = 39
Therefore, 39 + 29 + 19 = 87
Click here to post comments
Join in and write your own page! It's easy to do. How? Simply click here to return to Algebra word problems.
Sep 30, 22 04:45 PM
Learn to solve a great variety of permutation word problems with easy to follow explanations.