你能算得又对又快吗？ + = - =

1. 你能算得又对又快吗？
$\text{[math]}$ + $\text{[math]}$ = $\text{[math]}$ - $\text{[math]}$ = $\text{[math]}$ - $\text{[math]}$ = 1- $\text{[math]}$ = $\text{[math]}$ - $\text{[math]}$ =

$\text{[math]}$ - $\text{[math]}$ = $\text{[math]}$ + $\text{[math]}$ = 1- $\text{[math]}$ = $\text{[math]}$ + $\text{[math]}$ = $\text{[math]}$ - $\text{[math]}$ =