Question

a) (+5a²) + (-3a²) =
b) (+8x) - (-3x) =
c) (-5x) - (-11x) =
d) (-6y) - (-y) =

a ) 1by 15by
----- + ----- =
2 6

b) 32cz³ + 24cz³ =

c) Determine o valor da expressão algébrica 2x^4 + 4x - 5 com x = 3

Answer 1

a)
= (+5a²) + (-3a²)
= 5a² - 3a²
= 2a²
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
b)
= (+8x) - (-3x)
= 8x + 3x
= 11x

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨

c)
= (- 5x) - ( - 11x)
=  - 5x + 11x
= 6x 

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨

d)
= (-6y) - (-y)
= - 6y + y
= - 5y
********************************

a )
 1by    15by            3by + 15by    =  18by
----- +  ---------  =   ------------------      ----------  =  3by
   2         6                    6                        6

*************************************

b) 32cz³ + 24cz³ = 56 cz³

******************************************


c) Determine o valor da expressão algébrica 2x^4 + 4x - 5 com x = 3

2x⁴ + 4x - 5 = 2.(3)⁴ + 4.3 - 5 = 2.81 + 12 - 5 = 162 + 7 = 169