题目(1)(−2)2×5−(−2)3÷4(1)(-2{{)}^{2}}\times 5-(-2{{)}^{3}}\div 4(1)(−2)2×5−(−2)3÷4(2)3x−14−1=5x−76(2)\dfrac{3x-1}{4}-1=\dfrac{5x-7}{6}(2)43x−1−1=65x−7(3){3x=1−y2x−y=4(3)\left\{\begin{matrix}3x=1-y\\ 2x-y=4\\\end{matrix}\right.(3){3x=1−y2x−y=4(4){x:y:z=1:2:3x+2y−z=4(4)\left\{\begin{matrix}x:y:z=1:2:3\\ x+2y-z=4\\\end{matrix}\right.(4){x:y:z=1:2:3x+2y−z=4知识点：解二元一次方程组——加减消元法章节：方程与不等式 / 二元一次方程组
