Question

脱式计算（能简算的要简算）

7.8÷【32X（1-5/8）+3.6】 （0.98X99+0.98）÷49

4/11-6/13+7/9X（9/11-9/13） 9/13÷8+1/8X7/13

Answer 1

7.8÷【32X（1-5/8）+3.6】 （0.98X99+0.98）÷49
＝7.8÷[32X3/8+3.6] =0.98X(99+1)÷49
=7.8÷[12+3.6] =98÷49
=7.8÷15.6 =2
=0.5
4/11-6/13+7/9X（9/11-9/13） 9/13÷8+1/8X7/13
=4/11-6/13+7/11-7/13 =9/13X1/8+1/8X7/13
=(4/11+7/11)-(6/13+7/13) =1/8X(9/13+7/13)
=1-1 =1/8X16/13
=0 =2/13

Answer 2

（1）7.8÷【32X（1-5/8）+3.6】
=7.8÷[32×3/8+3.6]
=7.8÷15.6
=1/2

（2）（0.98X99+0.98）÷49
=0.98（99+1）÷49
=（0.98×100）÷49
=1/49

（3）4/11-6/13+7/9X（9/11-9/13）
=4/11-6/13+7/9*9/11-7/9*9/13
=4/11-6/13+7/11-7/13
=11/11-13/13
=1-1
=0

（4） 9/13÷8+1/8X7/13
=9/13×1/8+1/8×7/13
=1/8（9/13+7/13）
=1/8×16/13
=2/13

Answer 3

1,=7.8/(32-32*5+3.6)=7.8/(32-20+3.6)=7.8/(12+3.6)=7.8/(12+3.6)=7.8/(7.8*2)=0.5
2,=(0.98*100)/49=98/49=2
3,=(4*13-6*11)/(11*13)+7/9[(9*13-9*11)/(11*13)]=-13/143+14/143=1/143
4,=9/13*1/8+1/8*7/13=16/(13*18)=2/13