Explicação passo-a-passo:
[tex]\blue {{ _{\heartsuit} } \heartsuit_{\heartsuit} } \: \: \mathsf {OI, TUDO \: \: J\acute{O}IA \: ? \: \:\blue {{ _{\heartsuit} } \heartsuit_{\heartsuit} } }[/tex]
a)
[tex] \sf{10\cdot( - 2) + ( - 5)\cdot( - 4)} \\ \sf{10\cdot( - 2) +20} \\ \sf{ - 20 + 20} \\ \boxed{\red{ \sf{0}}}[/tex]
b)
[tex] \sf{9\cdot3 + 8\cdot( - 2)} \\ \sf{27 + 8\cdot( - 2)} \\ \sf{27 + ( - 16)} \\ \sf{27 - 16} \\ \boxed{\red{ \sf{11}}}[/tex]
[tex]\mathcal{ATT : ARMANDO}[/tex]
[tex]\mathfrak{\small04\diagup01\diagup2021} \\ \mathfrak{\small{10} :{40} \: \: am}[/tex]
