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4 votes
X + y = 3
x^2 + y^2 = 5
Solve

User AbiusX
by
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1 Answer

13 votes

Answer:

(1, 2 ), (2, 1 )

Explanation:

Given the 2 equations

x + y = 3 → (1)

x² + y² = 5 → (2)

Rearrange (1) expressing y in terms of x by subtracting x from both sides

y = 3 - x → (3)

Substitute y = 3 - x into (2)

x² + (3 - x)² = 5 ← expand and simplify left side

x² + 9 - 6x + x² = 5

2x² - 6x + 9 = 5 ( subtract 5 from both sides )

2x² - 6x + 4 ( divide through by 2 )

x² - 3x + 2 = 0 ← in standard form

(x - 1)(x - 2) = 0 ← in factored form

Equate each factor to zero and solve for x

x - 1 = 0 ⇒ x = 1

x - 2 = 0 ⇒ x = 2

Substitute these values into (3) for corresponding values of y

x = 1 : y = 3 - 1 = 2 ⇒ (1, 2 )

x = 2 : y = 3 - 2 = 1 ⇒ (2, 1 )

User Alisonthemonster
by
5.0k points