3. จงหาผลลัพธ์
1) [(-8.56) \(\div\) (-1.44)] x 0
ตอบ 0
2) (-0.2)[(-0.092) \(\div\) 0.23]
วิธีทำ
(-0.2)[(-0.092) \(\div\) 0.23]
= (-0.2)[-(\(\mathsf{\frac{0.092}{0.23} \times \frac{100}{100}}\))]
= (-0.2)[-(\(\mathsf{\frac{9.2}{23}}\))]
= (-0.2)(-0.4)
= (0.2)(0.4)
= 0.08
ตอบ 0.08
3) [(-8.5) + 6.2] \(\div\) (-2.3)
วิธีทำ
[(-8.5) + 6.2] \(\div\) (-2.3)
= [-(8.5 – 6.2)] \(\div\) (-2.3)
= (-2.3) \(\div\) (-2.3)
= 2.3 \(\div\) 2.3
= 1
= 2.3 \(\div\) 2.3
= 1
ตอบ 1
4) [(-1.2) x (-0.52)] \(\div\) (-0.6)
วิธีทำ
[(-1.2) x (-0.52)] \(\div\) (-0.6)
= (1.2 x 0.52) \(\div\) (-0.6)
= -(\(\mathsf{\frac{1.2 \times 0.52}{0.6}}\))
= -(\(\mathsf{\frac{1.2}{0.6} \times}\) 0.52)
= -(\(\mathsf{\frac{1.2}{0.6} \times \frac{10}{10} \times}\) 0.52)
= -(\(\mathsf{\frac{12}{6} \times}\) 0.52)
= -(2 x 0.52)
= -1.04
ตอบ -1.04
5) [1.35 \(\div\) (-0.45)](9)
วิธีทำ
[1.35 \(\div\) (-0.45)](9)
= [-(1.35 \(\div\) 0.45)](9)
= (- \(\mathsf{\frac{1.35}{0.45}}\)) x 9
= (- \(\mathsf{\frac{1.35}{0.45} \times \frac{100}{100}}\)) x 9
= (- \(\mathsf{\frac{135}{45}}\)) x 9
= (-3) x 9
= -27
ตอบ -27
6) (-1.01)[(-12.03) \(\div\) 12.03]
วิธีทำ
(-1.01)[(-12.03) \(\div\) 12.03]
= (-1.01)[-(12.03 \(\div\) 12.03)]
= (-1.01)(-1)
= (1.01)(1)
= 1.01
= (1.01)(1)
= 1.01
ตอบ 1.01