Răspuns :
a)3x-10x= -7x
b)-a-a=-2a
c)2y-3-y-3=y-3
d)√2x²+√8x² +√8x -7√2x= √2x² +2√2x² +2√2x -7√2x= √2x²(1+2)+√2x(2-7)=
=√2x² * 3+ √2x *(-5)= √2x(3*x-5)= √2x(3x-5)
e)1/2 *x + 2/3 *y -1 intreg 1/2 *x -5/2 *y= x/2 +2y/3 -3/2 *x -5y/2=
= x/2+2y/3 -3x/2 -5y/2= -2x/2 + ( 2y/3 -5y/2) aducem la acelasi numitor in paranteza=
= -x + (4y-15y)/6= -x -11y/6
f)2x * 3x²y= 6x³y
g) -2/3 *a⁵ * 9/8 * a⁷= -3/4 *a¹²
h)√2x²y * √2xy *√6x= 2x⁴y²√6
i) 25y⁵ : (-5y²)= 5²y⁵ :(-5y²)= -5y³
j) -1/2 *a⁴ :(3/4 *a²)= -1/2 *a⁴ *4/3 * 1/a²= -2/3 *a²
k)√6 a⁴b² : (√3ab²) = √2a³
l)(2√2xy²)²= 8x²y⁴
m)(-√3a²bc³ ) : (3√3a⁵b²c⁵)= -3a⁻³ b⁻¹c⁻²= - 1/(3a³bc²)
n)(-√5x²y³z)² :(-√20 x²y³z)= (5x⁴y⁶z²) :(2√5x²y³z)= (5x²y³z)/2√5 rationalizam
= 10√5x²y³z/2*5= √5x²y³z
b)-a-a=-2a
c)2y-3-y-3=y-3
d)√2x²+√8x² +√8x -7√2x= √2x² +2√2x² +2√2x -7√2x= √2x²(1+2)+√2x(2-7)=
=√2x² * 3+ √2x *(-5)= √2x(3*x-5)= √2x(3x-5)
e)1/2 *x + 2/3 *y -1 intreg 1/2 *x -5/2 *y= x/2 +2y/3 -3/2 *x -5y/2=
= x/2+2y/3 -3x/2 -5y/2= -2x/2 + ( 2y/3 -5y/2) aducem la acelasi numitor in paranteza=
= -x + (4y-15y)/6= -x -11y/6
f)2x * 3x²y= 6x³y
g) -2/3 *a⁵ * 9/8 * a⁷= -3/4 *a¹²
h)√2x²y * √2xy *√6x= 2x⁴y²√6
i) 25y⁵ : (-5y²)= 5²y⁵ :(-5y²)= -5y³
j) -1/2 *a⁴ :(3/4 *a²)= -1/2 *a⁴ *4/3 * 1/a²= -2/3 *a²
k)√6 a⁴b² : (√3ab²) = √2a³
l)(2√2xy²)²= 8x²y⁴
m)(-√3a²bc³ ) : (3√3a⁵b²c⁵)= -3a⁻³ b⁻¹c⁻²= - 1/(3a³bc²)
n)(-√5x²y³z)² :(-√20 x²y³z)= (5x⁴y⁶z²) :(2√5x²y³z)= (5x²y³z)/2√5 rationalizam
= 10√5x²y³z/2*5= √5x²y³z