125 \(\times\) 2 + 36  \(\times\) 2

= 250 + 72

= 322

Chọn B.322

F = − 2 7 . 5 13 − 9 15 − 2 7 . 8 13 F = − 2 7 . 5 13 − 3 5 − 2 7 . 8 13 F = − 2 7 . − 14 65 − 2 7 . 8 13 F = − 2 7 . − 14 65 + 8 13 F = − 2 7 . 2 5 = − 4 35

A = 51 − 314 + 213 ; A = 51 − 314 − 213 B = 51 + 213 − 314 ; C = 51 + 314 − 213 ; D = 51 + 213 − 314 ; D = 51 + 213 − 314 E = 51 − 314 − 213 ; E = 51 − 314 + 213 F = 51 − 213 − 314. V ậ y   A = F ;   B = E = D

a, A= x + (-37) - 235 = (-11) + (-37) - 235 = -48 - 235 = -283

b, A = x + (-37) - 235 = 187 - 37 - 235 = 150 - 235 = -85

\(A=426+2.\left(37-213\right)+39-13\)

\(A=426+2.\left(-176\right)+39-13\)

\(A=426+\left(-352\right)+39-13\)

\(A=74+39-13\)

\(A=113-13\)

\(A=100\)

\(B=\left(\frac{1}{2}-\frac{3}{11}\right):\frac{1}{22}-10\)

\(B=\frac{5}{22}:\frac{1}{22}-10\)

\(B=5-10\)

\(B=-5\)

A = 426 + 2 ( 37 - 213 ) + 39 - 13

   = 426 + 2.( - 176 ) + 39 - 13

   = 426 - 352 + 39 - 13

   = 74 + 39 - 13 

   = 113 - 13 

   = 100

Study well ! >_<

a )  = ( 25915 + 142 ) : 71

= 26057 : 71

=367

b ) đề sai

a: Ta có: \(A=\left(x-1\right)\left(x-3\right)+11\)

\(=x^2-4x+3+11\)

\(=x^2-4x+4+8\)

\(=\left(x-2\right)^2+8\ge8\forall x\)

Dấu '=' xảy ra khi x=2

b: Ta có: \(B=-4x^2+4x+5\)

\(=-\left(4x^2-4x+1-6\right)\)

\(=-\left(2x-1\right)^2+6\le6\forall x\)

Dấu '=' xảy ra khi \(x=\dfrac{1}{2}\)