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.
×37%+0.63×20%+43%;1 5
98%×
+2%×1 4
;1 4
80%x+90%x=68;
2x-60%x=9.6.
答
①
×37%+0.63×20%+43%1 5
=0.2×(37%+0.63)+43%
=0.2+0.43
=0.63;
②98%×
+2%×1 4
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