244 algebra De mystif ieD
number is eight more than this, so x + 8 represents the other number.
Their sum is 70, giving us x + (x + 8) = 70.
xx
x
x
x
x
++=
+=
−−
=
=
=
() 870
2870
88
262
62
2
31
The numbers are 31 and x + 8 = 31 + 8 = 39.
The sum of two numbers is 63. One of the numbers is twice the other.
Find the numbers.
Let x = first number, and 2x = other number.
Their sum is 63, so x + 2 x = 63.
xx
x
x
x
+=
=
=
=
263
363
63
3
21
The numbers are 21 and 2x = 2(21) = 42.
PRACTICE
- The sum of two numbers is 85. One number is 15 more than the other.
What are the two numbers? - The sum of two numbers is 48. One number is three times the other.
What are the numbers?
PRACTICE
- The sum of two numbers is 85. One number is 15 more than the other.