Question

Jika
1/4x + 7/2y = 5/4
1/2x - 3/y = -5/14
maka nilai x^2 + y^2 = ...

Answer 1

1/4x + 7/2y = 5/4    ⇔ 2/4x + 7/y = 35/14
1/2x - 3/y = -5/14    ⇔ 2/4x - 3/y = -5/14 -
                                         10/y = 40/14 = 20/7 ⇔ y = 7/2
1/4 x + 7/2 y = 5/4 ⇔ 1/4 x + 49/4 = 5/4 ⇔ 1/4 x = - 11 ⇔ x = -44
maka nilai x^2 + y^2 = (-44)² + (7/2)² = 1936 + 49/2 = 1960 1/2
maaf kalau salah

Answer 2

1/(4x) + 7/(2y) = 5/4 → Dikali 28xy
1/(2x) - 3/y = -5/14 → Dikali 14xy

Jadi,
7y + 98x = 35xy
7y - 42x = - 5xy
−−−−−−−−−−−−− −
140x = 40xy
7 = 2y
y = 7/2

7y + 98x = 35xy
y + 7x = 5xy
(7/2) + 7x = 5(7/2)x
7 + 14x = 35x
7x = 7
x = 1

x² + y² = ....?
x² + y² = (1)² + (7/2)²
x² + y² = + 49/4
x² + y² = 4/4 + 49/4
x² + y² = 53/4