计算. 1/5×37%+0.63×20%+43%; 98%×1/4+2%×1/4; 80%x+90%x=68; 2x-60%x=9.6.

问题描述:

计算.

1
5
×37%+0.63×20%+43%;
98%×
1
4
+2%×
1
4

80%x+90%x=68;
2x-60%x=9.6.

1
5
×37%+0.63×20%+43%
=0.2×(37%+0.63)+43%
=0.2+0.43
=0.63;
②98%×
1
4
+2%×
1
4

=(98%+2%)×
1
4

=
1
4

③80%x+90%x=68
  1.7x÷1.7=68÷1.7
          x=40;
④2x-60%x=9.6
1.4x÷1.4=9.6÷1.4
        x=
48
7