解一元一次方程——去分母练习题 (1)19/100x=21/100(x-2) (2)(x+1)/2-2=x/4 (3)(5x-1)/4=(3x+1)/2-(2-x)/3 (4)(3x+2)/2-1=(2x-1)/4-(2x+1)/5 答案 19/100x=21/100(x-2) 19/100x=[21(x-2)]/100 方程两边同时乘以100 19x=21(x-2) 19x=21x-42 21x-19x=42 2x=42 x=21 (x+1)/2-2=x/4 方程两边同时乘以4 2(x+1)-8=x 2x+2-8=x 2x-x=-2+8 x=6 (5x-1)/4=(3x+1)/2-(2-x)/3 方程两边同时乘以12 3(5x-1)=6(3x+1)-4(2-x) 15x-3=18x+6-8+4x 15x-3=22x-2 22x-15x=-3+2 7x=-1 x=-1/7 (3x+2)/2-1=(2x-1)/4-(2x+1)/5 方程两边同时乘以20 10(3x+2)-20=5(2x-1)-4(2x+1) 30x+20-20=10x-5-8x-4 30x=2x-9 30x-2x=-9 28x=-9 x=-9/28 本文来源:https://www.wddqw.com/doc/1c040af4f02d2af90242a8956bec0975f565a4a4.html