<span>x is the first number y is the second number z is the third number Given x + y + z = 6 (</span><span>The sum of three numbers is 6) </span>z = x + y (<span>the third number is the sum of the first and second numbers) </span><span>x = z + 1 (</span><span>the first number is one more than the third number) </span><span> x + y + z=6 z + z = 6 (because z = x + y) 2 z = 6
Divide both sides by 2 then z = 3
Replace z = 2 into </span>x = z+1 to find x x = 3 + 1 x = 4
Replace x = 4 , z = 3 into z = x + y to find y 3 = 4 + y
Subtract 4 to both sides 3 - 4 = 4 + y -4
Simplify -1 = y or y = -1
Answer x = 4, y = -1, z = 3
Proof: x + y + z = 6 (The sum of three numbers is 6) 4 + (-1) + 3 = 6 6 = 6
z = x + y (the third number is the sum of the first and second numbers) 3 = 4 + (-1) 3 = 3
x = z + 1 (the first number is one more than the third number) 4 = 3 + 1 4 = 4
