The difference between two positive integers is 3. If the smaller is added to the square of the larger, the sum is 339. Find the integers.?
回答 (4)
Set your variables. Let x equal the larger and y equal the lower.
The difference of the two is three. so x - y = 3
And x^2 + y =339
Solve the first equation for y and insert into the second. y = x - 3
So x^2 + x - 3 = 339
Subtract 339 from both sides. x^2 + x - 342 = 0
Factor out (x+19)(x-18) = 0
Thus x is 18 and -19 but the question ask for two positive values so drop the negative one and use the first equation to solve for y
x = 18, y = 15
x+(x+3)^2 = 339
x^2+7x-330 =0
(x+22)(x-15) = 0
x = 15
Numbers are 15 and 18
y = x + 3
y^2 + x = 339
(x+3)^2 + x = 339
x^2 + 7x - 330 = 0
x = 15, -22
x = 15, y = 18
quadratic equation:
given that n-k=3
n+ k^2 =339
so 3+k=339-k^2
k^2+k-333=0
k=-1/2 +/- sqrt(1333)/2
take the positive number
收錄日期: 2021-05-01 15:20:02
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