a)36.4²+64.2⁴=36.16+64.16=16(64+36)=16.100=1600

b)70-36(3+12)=34.15=510

c)15+(35-10:5)=15+33=48

Cách cuối không nhanh lắm nhưng cho mình xin một tick nha!

I am English' teacher

3/15 chia cả mẫu cả tử cho 3 được 1/5+2/5=3/5 nhé

 = ( -2 + 4) + ( -6 +8) + ...+(-18 + 20 ) 

= 2+2+2+2+2

= 10

= [-2 + 4] + [-6+8] + ... +[-18 + 20]

= 2 + 2 + ... + 2 

= 10

4 x 5 + 10 = 20 + 10 = 30

3 x 9 – 20 = 27 – 20 = 7

(-2) + 4 + ( -6) + 8 + (-10) + 12 + (-14) + 16 + (-18) + 20

=[(-2) + 12] + [4+(-14)] + [(-6)+16] + [8+(-18)] + [(-10)+20]

=    10        +     (-10)    +    10       +    (-10)    +    10

=(10 +10 +10) + [(-10) + (-10)]

=    30             +      (-20)

=              10

Ta có:

\(\frac{1}{x-1}-\frac{2x}{x^3-x^2+x-1}\)

\(=\frac{1}{x-1}-\frac{2x}{x^2\left(x-1\right)+\left(x-1\right)}\)

\(=\frac{x^2+1}{\left(x-1\right)\left(x^2+1\right)}-\frac{2x}{\left(x^2+1\right)\left(x-1\right)}\)

\(=\frac{x^2+1-2x}{\left(x-1\right)\left(x^2+1\right)}\)

\(=\frac{\left(x-1\right)^2}{\left(x-1\right)\left(x^2+1\right)}=\frac{x-1}{x^2+1}\)

\(60\%:\left(12\times5\right)+75\%\)

\(=\frac{3}{5}:60+\frac{3}{4}\)

\(=\frac{3}{5}.\frac{1}{60}+\frac{3}{4}\)

\(=\frac{1}{100}+\frac{3}{4}\)

\(=\frac{1}{100}+\frac{75}{100}\)

\(=\frac{76}{100}\)

60%:(12x5)+75%

=60/100:60+0,75

=    0,01     +0,75

=       0,76.

K nhé vegeta.

\(\frac{4^5.9^5-2.6^{10}}{2^{10}.3^9+6^9.20}=\frac{\left(4.9\right)^5-2.2^{10.}.3^{10}}{2^{10}.3^9+2^9.3^9.2^2.5}\)

\(\frac{2^{10}.3^{10}^{ }-2^{11}.3^{10}}{2^{10}.3^9+2^{11}.3^9.5}=\frac{2^{10}.3^{10}\left(1-2\right)}{2^{10}.3^9\left(1+2.5\right)}\)

\(\frac{2^{10}.3^{10}.\left(-1\right)}{2^{10}.3^9.\left(-9\right)}=\frac{-3}{-9}=\frac{1}{3}\)