quá ez

a) 15,32 + 27,4 – 4,25 × 2

= 42,72 – 8,5

= 34,22.

b) (227,45 − 142,65) : 3,2 – 25

= 84,8 : 3,2 – 25

= 26,5 – 25

= 1,5.

(12,4+8,6)×8,5:2=89,25(m2)

Diện tích đài phun nước là:

\(2 \times 2 \times 3 , 14 = 12 , 56 \left(\right. m^{2} \left.\right)\)

Diện tích phần còn lại là:

89,25-12,56=76,69(m²)

AD=AM+MD=10+15=25(cm)

\(S_{A B C D} = A B \times A D\)

=>\(A B = \frac{1000}{25} = 40 \left(\right. c m \left.\right)\)

=>DC=40(cm)

\(S_{M D C} = \frac{1}{2} \times M D \times D C = \frac{1}{2} \times 15 \times 40 = 20 \times 15 = 300 \left(\right. c m^{2} \left.\right)\)

AD=AM+MD=10+15=25(cm)

\(S_{A B C D} = A B \times A D\)

=>\(A B = \frac{1000}{25} = 40 \left(\right. c m \left.\right)\)

=>DC=40(cm)

\(S_{M D C} = \frac{1}{2} \times M D \times D C = \frac{1}{2} \times 15 \times 40 = 20 \times 15 = 300 \left(\right. c m^{2} \left.\right)\)

a: 15,6+32,88=48,48

b: 158,08-97,15=60,93

c: 15,45x1,6=24,72

d: 75:60=1,25

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