\(-237\)

-237

a) (-28) + (-35) – 92 + (-82) = -28 – 35 – 92 – 82 

= - (28 + 35 + 92 + 82) = - [(28 + 82) + (35 + 92)]

= - (110 + 127) = - 237.

b) 15 – (-38) + (-55) – (+47) = 15 + 38 – 55 – 47

= - 2 – 47 = - (2 + 47) = - 49

a) (-28) + (-35) – 92 + (-82) = -28 – 35 – 92 – 82 

= - (28 + 35 + 92 + 82) = - [(28 + 82) + (35 + 92)]

= - (110 + 127) = - 237.

b) 15 – (-38) + (-55) – (+47) = 15 + 38 – 55 – 47

= 53 – 55 – 47 = - (55 – 53) – 47

= - 2 – 47 = - (2 + 47) = - 49

\(\frac{x+91}{81}+\frac{x+92}{82}+\frac{x+93}{83}=3\)

\(\frac{x+91}{81}-1+\frac{x+92}{82}-1+\frac{x+93}{83}-1=0\)

\(\frac{x+10}{81}+\frac{x+10}{82}+\frac{x+10}{83}=0\)

\(\left(x+10\right)\left(\frac{1}{81}+\frac{1}{82}+\frac{1}{83}\right)=0\)

=> x + 10 = 0 (vì \(\left(\frac{1}{81}+\frac{1}{82}+\frac{1}{83}\right)\ne0\))=> x = -10

E=92x164-64x(82+10)

E=92x164-64x92

E92x(164-64)

E=92x100

E=9200.

k minh voi.

E=9200

82+92(x^2xx) = 0

x^2xx = 0

x=  0 

Sai hết! Không tìm được x thỏa mãn vì 92(x^2.xx) luôn luôn lớn bằng 0 nên 82+92(x^2.xx) luôn lớn bằng 82.

a,  13 2 = 169 < 216 = 13 2

b,  6 2 + 8 2 = 100 < 196 =  6 + 8 2

c,  13 2 - 9 2 = 88 > 16 =  13 - 9 2

d,  a 2 + b 2 <  a 2 + b 2 + 2 a b = a + b 2 a ; b ∈ N *

Đáp án C

ketquaC