Tính
98% - 43% = ………….
Cho biểu thức: 234 x 43 + 234 x 57. Cách tính đúng là: *
A. 234 x 43 + 234 x 57 = 234 x 43 + 234 = 10 296
B. 234 x 43 + 234 x 57 = 234 x 43 + 57 = 10 119
C. 234 x 43 + 234 x 57 = 234 x (57 – 43) = 3 276
D. 234 x 43 + 234 x 57 = 234 x (43 + 57) = 23 400
36 * 43 + 43 * 58 +43 * 5 + 43
36x43+43x58+43x5+43
=43x(36+58+5+1)
=43x100
=4300
36x43+43x58+43x5+43
=(36+58+5) x43+43
=99x43+43
=(100-1)x43+43
=100x43-43x1+43
=4300-43+43
=4300
CMR: (43^3+17^3)/(43^3+26^3)=(43+17)/(43+26)
\(VT=\frac{\left(43+17\right)\left(43^2-43.17+17^2\right)}{\left(43+26\right)\left(43^2-43.26+26^2\right)}=\frac{\left(43+17\right)\left[43^2-17\left(43-17\right)\right]}{\left(43+26\right)\left[43^2-26\left(43-26\right)\right]}.\)
\(VT=\frac{\left(43+17\right)\left(43^2-17.26\right)}{\left(43+26\right)\left(43^2-26.17\right)}=\frac{43+17}{43+26}=VP\left(dpcm\right)\)
-43 . 38 + 12 . (-43) - 50 . (-43)
\(=-43\cdot\left(38+12-50\right)=-43\cdot0=0\)
a. (42 . 43 + 43 . 57 + 43) – 360 : 4
\(\left(42\cdot43+43\cdot57+43\right)-360:4\)
\(=43\cdot\left(42+57+1\right)-90\)
\(=42\cdot100-90\)
=4110
43*42+57*43+43
43*42+57*43+43
= 43 * ( 42 + 57 + 1)
= 43 * 100
= 4300
43 x 42 + 57 x 43 + 43 = 43 x (42 + 57 + 1) = 43 x 100 = 4300 (k cho tớ với nhá!)
Tính thuận tiện:
43 x 95 + 43 x 4 + 43
CMR : \(\frac{43^3+17^3}{43^3+26^3}=\frac{43+17}{43+26}\)
\(\frac{43^3+17^3}{43^3+26^3}=\frac{\left(43+17\right)\left(43^2-43×17+17^2\right)}{\left(43+26\right)\left(43^2-43×26+26^2\right)}=\frac{\left(43+17\right)×1407}{\left(43+26\right)×1407}=\frac{43+17}{43+26}\left(dpcm\right)\)
Tính bằng cách thuận tiện nhất
1 3 × 4 3 + 4 3 × 5 3 + 4 3 + 2 =
cmr (43 ngu 43+17 ngu 43) chia het cho10