Two fifths of the number a is less than one-half of the number B by 5. Given that the number B is 20, find the number a

Two fifths of the number a is less than one-half of the number B by 5. Given that the number B is 20, find the number a

Let a be X
1/2*20-2/5x=5
The solution is x = 12.5

3.2 × 0.25 × 0.125 (simple calculation)

3.2×0.25×0.125
=0.4×0.25×8×0.125
=0.1×1
=0.1

3.2 × 0.25 × 0.125 (simple calculation) (writing process)

3.2×0.25×0.125
=0.4×0.25×8×0.125
=0.1×1
=0.1

25 + 125 * 3.2 simple operation

25+125*3+125*0.2=25+375+25=425
I don't know if it's easy enough

Simple calculation: [5-3 and 7 / 8 ÷ (1 and 5 / 6 + 2.25 × 1 / 3)] 0.125

[5-3 + 7 / 8 (1 + 5 / 6 + 2.25 × 1 / 3)] 0.125
=[5-3 and 7 / 8 △ (11 / 6 + 9 / 4 × 1 / 3)] 1 / 8
=【5-31/8÷(11/6+9/4×1/3)】×8
=【5-31/8÷(11/6+3/4)】×8
=【5-31/8÷(31/12)】×8
=【5-3/2】×8
=40-12
=28

39.7 × 2.8 + 3.97 × 72

39.7×2.8+3.97×72
=3.97×10×2.8+3.97×72
=3.97×28+3.97×72
=3.97×（28+72）
=3.97×100
=397

How to calculate 72 × 39 + 72 simply?
Use the ladder equation!

72×39+72
=72x(39+1)
=72x40
=2880

Simple calculation of 39 * 8 + 6 * 39-39-4

39*8+6*39-39-4
=39×（8+6-1）-4
=39×13-4
=503

How to use recursive equation to calculate 45 times 45 + 55 times 45

55 times 45 minus 45 times 45 simple calculation with recursive equation