Question

2 - Qual o valor da expressão -0,45 – 1,2? 1 ponto a) -1,65 b) -0,75 c) -0,37 d) 0,37.

Answer 1

$\Large\boxed{\begin{array}{l}\underline{\rm Adic_{\!\!,}\tilde ao\,alg\acute ebrica\,de\,n\acute umeros\,racionais}\\\sf Sinais\,iguais: soma-se\,e\,repete-se\,o\,sinal.\\\sf ex: -13-2=-15\\\sf Sinais\,diferentes: Diminui \,da\,o\,sinal\,de\,quem\\\sf tiver\,o\,maior\,m\acute odulo.\\\sf ex:2-6=-4\end{array}}$

$\Large\boxed{\begin{array}{l}\rm2- Qual\,o\,valor\,da\,express\tilde ao\,-0,45-1,2?\\\rm a)-1,65\checkmark\\\rm b)-0,75\\\rm c)-0,37\\\rm d)0,37\\\underline{\boldsymbol{soluc_{\!\!,}\tilde ao\!:}}\\\sf 0,45-1,2\\\sf vamos\,completar\,com\,0\,o\,segundo\,n\acute umero:\\\sf -0,45-1,20.\\\sf observe\,que\,os\,sinais\,s\tilde ao\,iguais\\\sf portanto\,vamos\,somar\,e\,repetir\,o\,sinal.\\\sf 0,45+1,20=1,65\\\sf repetindo\,o\,sinal\,temos:\\\sf -0,45-1,20=-1,65\checkmark\\\Huge\boxed{\boxed{\boxed{\boxed{\sf\maltese~alternativa~a}}}}\end{array}}$