Tính a,(-3x+5)^2 b,(2x+1/2)^2 c(2x-1)^2-(x-3)^2 d,(3x^2-1/2^3)+(x^3+1/4)^2 e,(a-3)+(a+1)^3 06/08/2021 Bởi Charlie Tính a,(-3x+5)^2 b,(2x+1/2)^2 c(2x-1)^2-(x-3)^2 d,(3x^2-1/2^3)+(x^3+1/4)^2 e,(a-3)+(a+1)^3
Giải thích các bước giải: a/ $(-3x+5)^2=(5-3x)^2=5^2-2.5.3x+(3x)^2=25-30x+9x^2$ b/ $(2x+\dfrac{1}{2})^2=(2x)^2+2.2x.\dfrac{1}{2}+(\dfrac{1}{2})^2=4x^2+2x+\dfrac{1}{4}$ c/ $(2x-1)^2-(x-3)^2$ $=(2x)^2-2.2x+1-(x^2-2.3x+3^2)$ $=4x^2-4x+1-x^2+6x-9$ $=3x^2+2x-8$ d/ $(3x^2-\dfrac{1}{2^3})+(x^3+\dfrac{1}{4})^2$ $=3x^2-\dfrac{1}{8}+x^6+\dfrac{1}{2}.x^3+\dfrac{1}{16}$ $=x^6+\dfrac{1}{2}x^3+3x^2-\dfrac{1}{16}$ e/ $(a-3)+(a+1)^3=a-3+a^3+3a^2+3a+1=a^3+3a^2+4a-2$ Chúc bạn học tốt !!! Bình luận
a) $(-3x+5)^2$ $=9x^2-30x+25$ b) $(2x+\dfrac{1}{2})^2$ $=4x^2+2x+\dfrac{1}{4}$ c) $(2x-1)^2-(x-3)^2$ $=4x^2-4x+1-(x^2-6x+9)$ $=3x^2+2x-8$ d) $(3x^2-\dfrac{1}{2^3})+(x^3+\dfrac{1}{4})^2$ $=3x^2-\dfrac{1}{8}+x^6+\dfrac{1}{2}x^3+\dfrac{1}{16}$ $=x^6+\dfrac{1}{2}x^3+3x^2-\dfrac{1}{16}$ e) $(a-3)+(a+1)^3$ $=a-3+a^3+3a^2+3a+1$ $=a^3+3a^2+4a-2$ Bình luận
Giải thích các bước giải:
a/ $(-3x+5)^2=(5-3x)^2=5^2-2.5.3x+(3x)^2=25-30x+9x^2$
b/ $(2x+\dfrac{1}{2})^2=(2x)^2+2.2x.\dfrac{1}{2}+(\dfrac{1}{2})^2=4x^2+2x+\dfrac{1}{4}$
c/ $(2x-1)^2-(x-3)^2$
$=(2x)^2-2.2x+1-(x^2-2.3x+3^2)$
$=4x^2-4x+1-x^2+6x-9$
$=3x^2+2x-8$
d/ $(3x^2-\dfrac{1}{2^3})+(x^3+\dfrac{1}{4})^2$
$=3x^2-\dfrac{1}{8}+x^6+\dfrac{1}{2}.x^3+\dfrac{1}{16}$
$=x^6+\dfrac{1}{2}x^3+3x^2-\dfrac{1}{16}$
e/ $(a-3)+(a+1)^3=a-3+a^3+3a^2+3a+1=a^3+3a^2+4a-2$
Chúc bạn học tốt !!!
a) $(-3x+5)^2$
$=9x^2-30x+25$
b) $(2x+\dfrac{1}{2})^2$
$=4x^2+2x+\dfrac{1}{4}$
c) $(2x-1)^2-(x-3)^2$
$=4x^2-4x+1-(x^2-6x+9)$
$=3x^2+2x-8$
d) $(3x^2-\dfrac{1}{2^3})+(x^3+\dfrac{1}{4})^2$
$=3x^2-\dfrac{1}{8}+x^6+\dfrac{1}{2}x^3+\dfrac{1}{16}$
$=x^6+\dfrac{1}{2}x^3+3x^2-\dfrac{1}{16}$
e) $(a-3)+(a+1)^3$
$=a-3+a^3+3a^2+3a+1$
$=a^3+3a^2+4a-2$