Đáp án:
${a,}$ $(-\dfrac{1}{3}+$ $\dfrac{5}{6}).11-7=$ $-\dfrac{3}{2}$
${b,}$ $-\dfrac{5}{11}.$ $\dfrac{7}{15}.$ $(-\dfrac{11}{5}).(-30)=-14$
Giải thích các bước giải:
Bài 1:
${a,}$ $(-\dfrac{1}{3}+$ $\dfrac{5}{6}).11-7$
${=}$ $(-\dfrac{2}{6}+$ $\dfrac{5}{6}).11-7$
${=}$ $\dfrac{1}{2}.11-7$
${=}$ $\dfrac{11}{2}-7$
${=}$ $-\dfrac{3}{2}$
Bài 2:
${A=}$ $-\dfrac{5}{11}.$ $\dfrac{7}{15}.$ $(-\dfrac{11}{5}).(-30)$
${A=[}$ $-\dfrac{5}{11}.$ $(-\dfrac{11}{5})].[$ $\dfrac{7}{15}.(-30)]$
${A=1.(-14)}$
${A=-14}$
~Xin hay nhất~
