242 algebra De mystif ieD
PRACTICE- Find two consecutive numbers whose sum is 57.
- Find three consecutive numbers whose sum is 48.
- Find four consecutive numbers whose sum is 90.
✔SOLUTIONS
- Let x = first number, and x + 1 = second number.
Their sum is 57, so x+ (x+ 1) = 57.
xx
x
xxx++=
+=
−−
===() 157
2157
11
256
56
2
28
The first number is 28 and the second is x+ 1 = 28 + 1 = 29.- Let x = first number, x + 1 = second number, and x + 2 = third number.
Their sum is 48, so x+ (x + 1) + (x + 2) = 48.
xx x
xxxx++++=
+=
−−
===() 12 () 48
3348
33
345
45
3
15The first number is 15; the second, x+ 1 = 15 + 1 = 16; and the third,
x + 2 = 15 + 2 = 17.PRACTICE- Find two consecutive numbers whose sum is 57.