Question

Calculati:
a) (5√2 - 3√2)x + (6√2 - 4√2)x - (7√2 - √2) x + 4√2x
b) (2√20 + √80)xy - √45xy + √125xy + (√5 + √180)xy
c) √6x^2 + (√192 - √54) x^2 + 2√150x^2 + 7√3x^2 - 2√75x^2

Se considera numerele A= a^2 + x + 2, B= 3a^2 + 2x - 7, C= 4x + 12
Calculati:
a) A+B
b) A-B
c) A+B+C
d) A+(B-C)
e) -A+B-C
f) (A-B)+(B-C)+(C-A)

Answer 1

a) (5√2 - 3√2)x + (6√2 - 4√2)x - (7√2 - √2) x + 4√2x=
=5x√2 - 3x√2 + 6x√2 - 4x√2 - 7x√2 + x√2 + 4x√2=
=2x√2

b) (2√20 + √80)xy - √45xy + √125xy + (√5 + √180)xy=
=2xy√20 + xy√80 - xy√45 + xy√125 + xy√5 + xy√180=
=4xy√5 + 4xy√5 - 3xy√5 + 5xy√5 + xy√5 + 6xy√5=
=17xy√5


 c) √6x² + (√192 - √54) x² + 2√150x² + 7√3x² - 2√75x²=
=x²√6 + 8x²√3 - 3x²√6 + 10x²√6 + 7x²√3 - 10x²√3=
= 5x²√3  + 8x²√6


Se considera numerele A= a² + x + 2, B= 3a² + 2x - 7, C= 4x + 12
Calculati:
a) A+B=a² + x + 2+3a² + 2x - 7=4a²+3x-5
 b) A-B=a² + x + 2-3a² - 2x + 7=-2a² - x + 9
 c) A+B+C=4a² +3 x -5+4x+12=4a²+7x+7
 d) A+(B-C)=4a²+3x-5-4x-12=4a²-x-17
 e) -A+B-C=-(A-B)-C=-(-2a² - x + 9)-4x-12=2a²+x-9-4x-12=2a²-3x-21
 f) (A-B)+(B-C)+(C-A)=A-B+B-C+C-A=0