Question

X+2y=4. -X+2y=3. ??????????

Answer 1

Resposta:

$x + 2y = 4 \\ - x + 2y = 3 \\ 2y = 3 + x \\ x + 3 + x = 4 \\ 2x = 4 - 3 \\ 2x = 1 \\ x = \frac{1}{2} \\ 2y = 3 + \frac{1}{2} = 3 \frac{1}{2} = \frac{7}{2} \\ 2y \div 2 = \frac{7}{2} \div 2 \\ y = \frac{7}{4}$