How to do these two questions? Use a simple method to calculate (1): 57.6 × 1.6 + 28.8 × 36.8-14.4 × 80 How to do these two questions? Calculation by simple method (1):57.6×1.6+28.8×36.8-14.4×80 (2) The fourth power of 39 × 37-13 × 3

How to do these two questions? Use a simple method to calculate (1): 57.6 × 1.6 + 28.8 × 36.8-14.4 × 80 How to do these two questions? Calculation by simple method (1):57.6×1.6+28.8×36.8-14.4×80 (2) The fourth power of 39 × 37-13 × 3

57.6x1.6+28.8x36.8-14.4x80
=57.6x1.6+28.8x2x18.4-14.4x4x20
=57.6x1.6+57.6x18.4-57.6x20
=57.6x(1.6+18.4-20)
=0
39x37-13x3x3x3x3
=39x37-39x27
=39x(37-27)
=390

It is calculated by simple method: 57.6 × 1.6 + 28.8 × 36.8-14.4 × 80.5

57.6×1.6+28.8×36.8-14.4×80=57.6×1.6+28.8×2×18.4-14.4×4×20=57.6×1.6+57.6×18.4-57.6×20=57.6×（1.6+18.4-20）=0

It is calculated by simple method: 57.6 × 1.6 + 28.8 × 36.8-14.4 × 80.5

57.6×1.6+28.8×36.8-14.4×80=57.6×1.6+28.8×2×18.4-14.4×4×20=57.6×1.6+57.6×18.4-57.6×20=57.6×（1.6+18.4-20）=0