Sagot :
Bonjour,
(2x-1)(5x+3)
a)
x= 2
(4-1)( 10+3)=
3 *13 = 39
(2x-1)(5x+3) =39
b)
x= -4
(-8 -1) ( -20+3)=
-9 * -17 = 153
(2x-1)(5x+3) = 153
c)
x= 1/2
2*1/2 -1 = 2/2-1 = 1-1 = 0
donc (2x-1)(5x+3) = 0
d)
x= -3/5
2*-3/5 -1 = -6/5 -5/5 = -1/5
5*-3/5 +3 = -15/5 +3 = -3+3 = 0
donc (2x-1)(5x+3) = 0
1. A= (2x-1)(5x+3)
a. Pour x =2
A = (2*2-1)(5*2+3) =(4-1)*(10+3) = 3*13= 39.
b. Pour x = -4
A = (2*(-4)-1)(5*(-4)+3)=(-8-1)(-20+3)=-9*(-17)=153
a. Pour x =2
A = (2*2-1)(5*2+3) =(4-1)*(10+3) = 3*13= 39.
b. Pour x = -4
A = (2*(-4)-1)(5*(-4)+3)=(-8-1)(-20+3)=-9*(-17)=153