Question

Calcule o valor numérico das expressão 5x²-3x+2 nos casos : 
 A) x= -5 
B) x= 3 
C) x= -2
D)X=4
E)x=5

Answer 1

A)5.25-3.(-5)+2=125+17=142
B)5.9-3(3)+2=45-7=38
C)5.4-3(-2)+2=20+8=28
D)5.16-3.(4)+2=80-10=70
E)5.25-3(5)+2=125-13=112

Answer 2

 A) x= -5 
5x²-3x+2 
5.(-5)² -3.(-5)+2
5.(25) +15 +2
125 + 17
142

B) x= 3 
5x²-3x+2
5.(3)² -3.(3) +2
5.(+9) -9 +2
45 -9 +2
45 +2 -9
47 -9
38

C) x= -2
5x²-3x+2
5.(-2)² -3.(-2) +2
5.(+4) +6 +2
20 +6+2
28

D)X=4
5x²-3x+2
5.(4)² -3.(4) +2
5.(16) -12 +2
80 -12+2
80+2 -12
82 -12
70

E)x=5
5x²-3x+2
5.(5)² -3.(5) +2
5.(25) -15 +2
125 +2 -15
127 -15
112