Question

1) (-12.4+8.9)*

Answer 1

$( - 12.4 + 8.9) \times 1 \frac{3}{7} = - 3.5 \times \frac{10}{7} = - \frac{35}{10} \times \frac{10}{7} = - 5$

Answer 2

It seems like you provided an incomplete mathematical expression. Did you intend to multiply the result of the expression $(-12.4+8.9)$ by something? If so, could you please specify the factor or the complete expression you'd like to calculate?