Question

初一数学题 求解

(-a)^5·(-a)^3·a^2
28a^4b^2÷7a^3b
(-x-2y)(-x+2y)
(-1/2x-1/5y)^2
若x^(3n)=3，则x(6n)=
若16^2×8^3=2^n，则n=
(1.25×10^8)×(-8×10^5)×(-3×10^3)=
(-1/2x^2y^3)×(1/5x^2-2xy+1/3)=

Answer 1

(-a)^5·(-a)^3·a^2=（-a)^(5+3+2)=(-a)^10=a^10
28a^4b^2÷7a^3b=4ab
(-x-2y)(-x+2y)=(-x)^2-(2y)^2=x^2-4y^2
(-1/2x-1/5y)^2=[(-5y-2x）/10xy]^2=(25y^2+20xy+4y^2)/100x^2y^2
若x^(3n)=3，则x(6n)=[x^(3n)]^2=9
若16^2×8^3=2^n，则n=17
(1.25×10^8)×(-8×10^5)×(-3×10^3)=1.25*8*3*10^(8+5+3)=30*10^16
(-1/2x^2y^3)×(1/5x^2-2xy+1/3)=-1/10x^4y^3+x^3y^4-1/6x^2y^3

Answer 2

(-a)^5·(-a)^3·a^2=a^10

28a^4b^2÷7a^3b=4ab

(-x-2y)(-x+2y)=x^2-4y^2

Answer 3

(-a)^5·(-a)^3·a^2=a^10
28a^4b^2÷7a^3b=4ab
(-x-2y)(-x+2y)=x²-4y²
(-1/2x-1/5y)^2=1/4x²+1/5xy+1/25y²
若x^(3n)=3，则x(6n)=3²=9
若16^2×8^3=2^17=2^n，则n=17
(1.25×10^8)×(-8×10^5)×(-3×10^3)=3×10^17
(-1/2x^2y^3)×(1/5x^2-2xy+1/3)=-1/10x^4y^3+x³y^4-1/6x²y³

Answer 4

正在慢慢解决