Question

If the sum of two numbers is 4 and the sum of their squares minus three times their product is 76, find the numbers.​

Answer 1

Answer:

X and y = -2 or 6

Step-by-step explanation:

Answer 2

I'll be referring to each of these numbers as x and y.

x + y = 4

(x^2) + (y^2) - 3(x)(y) = 76

x = 4 - y

(4 - y)^2 + (y^2) - 3(4 - y)(y) = 76

(4 - y)(4 - y) + y^2 - (3y)(4 - y) = 76

16 - 4y - 4y + y^2 + y^2 - 12y + 3y^2 = 76

16 - 20y + 5y^2 = 76

5y^2 - 20y - 60 = 0

y^2 - 4y - 12y = 0

(y - 6)(y + 2) = 0

y = 6 or -2

x = 4 - 6 = -2

x = 4 - - 2 = 6

As you can see, we got the same numbers for both x and y, -2 and 6. Therefore, the two numbers are -2 and 6. But, we can check our work to ensure that the answer is correct.

x = -2

y = 6

6 - 2 = 4

4 = 4

(-2)^2 + (6^2) - 3(-2)(6) = 76

4 + 36 - 3(-12) = 76

40 + 36 = 76

76 = 76

Hope this helps!