Question

Calculati:
a)3x-10x=x(3-10) = x*(-7)= -7x 
b)-a-a= -2a 
c)2y-3-(y+3)
d)√2x² + √8x² + √8x -7√2x
e) $\frac{1}{2}$ din x + $\frac{2}{3}$ din y - 1 intreg si $\frac{1}{2}$ din x - $\frac{5}{2}$ din y
f) 2x * 3x²y 
g) -2/3 din a la puterea 5 * 9/8 din a la puterea 7 
h)√2x²y * √2xy * √6x 
i)25y la puterea 5 : (-5y²) 
j)-1/2 din a la puterea 4 : (3/4 din a²) 
k)√6 a la puterea 4 b² : (√3ab²) 
l)(2√2xy²)² 
m)(-√3a²bc la puterea 3) ³ : (3√3a la puterea 5 b² c la puterea 5)
n) (-√5x²y³z)² : (-√20x²y³z)

Answer 1

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