4.
(-3a²b)*(-5abc)=15a³b²c
-6x³yz² *(-2ax²y)=12ax⁵y²z²
√3 xy² *(√3 x³yz)=3x⁴y³z
13xy² *(-2x³y)=-26x⁴y³
x²y *(x²y)*(-2x²y)=-2x⁶y³
-ab²*(-ab)*(5a²b)=5a⁴b⁴
5.
2x(5-x)=10x-2x²
-2x²(4x-5)=-8x³+10x²
-2x*(x²-3x+1)=-2x³+6x²-2x
5xy²(2x+3y)=10x²y²+15xy³
-7xy²*(-1+x-2y²)=7xy²-7x²y²+14xy⁴
(3a²b)*(a²-b+2)=3a⁴b-3a²b²+6a²b
6.
5(x+1)-5 =5x+5-5=5x
2x(a+b)-x(a-b)=2ax+2bx-ax+bx=ax+3bx
(x+2)(x-1)-x²=x²+2x-x-2-x²=x-2
(-x)²-2x(x-1)=x²-2x²+2x=-x²+2x
(4x²+3x):x-2x=4x+3-2x=2x+3
(21x³-7x²):(-7x)=-3x²+x
(a³)²-(a²)³=a⁶-a⁶=0
(x³)²:x⁴- x(x-3)-3x=x⁶:x⁴-x²+3x-3x=x²-x²=0
(-3x)²-2x(3x-1)=9x²-6x²+2x=3x²+2x
7.
2a²*(3ab):6a²b)=6a³b:6a²b=a
(-13a⁵b):(-13a⁵)*(2ab)=b⁴*(2ab)=2ab⁵
(-2x)*(-2x²)*(-10x³):(-20x⁵)=-40x⁶ :(-20x⁵)=2x
√3x²*(-2x³*y²):(√3x⁴y²)=-2√3x⁵y²:(√3x⁴y²)=-2x
5x/7*(21x²y/20):(-3x³y/4)=3x³y/4 ×(-4/3x³y)=-1
(-2ab³c⁵/3)⁴=16a⁴b¹²c²⁰/81
(3ab²/2)⁻¹ :(3a²b⁻³/10)⁻¹=2/3ab² × 10b³/3a²=20b/9a³
{[6a³b³:(-3a²b²)]²}⁻¹={[6a³b³:(-3a²b²)]²}⁻¹=((-2ab)²}⁻¹=(4a²b²)⁻¹=1/4a²b²
