a) `(5x+2y)^2 = 25x^2 + 20xy + 4y^2`
b) `(-3x + 2)^2 = 9x^2 - 12x + 4`
c) `(2/3 x+1/3 y)^2 = 4/9 x^2 + 4/9 xy + 1/9 y^2`
d) `(2x-5/2y)^2 = 4x^2 - 10xy + 25/4 y^2`
e) `(x+4/3 y^2)^2 = x^2 + 8/3 y^2 + 16/9 y^4`
Đáp án:
Giải thích các bước giải:
A,(5x+2y)^2
⇔ 25x^2+20xy+ 4y^2
B,(-3x+2)^2
⇔ 9x^2-12x+4
C,($\frac{2}{3}$x +$\frac{1}{3}$ )^2
⇔$\frac{4}{9}$x^2+ $\frac{4}{9}$xy+ $\frac{1}{9}$y^2
D,(2x-$\frac{5}{2}$y)^2
⇔ 4x^2-10xy+$\frac{25}{4}$y^2
E,(x+$\frac{4}{3}$y^2)^2
⇔x^2+$\frac{8}{3}$x.y^2+ $\frac{16}{9}$y^4
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