Question
je n'arrive pas a résoudre les équations suivantes :
49=4x(au carré)
-x(au carré)+x-8=-8
2(x+3)+5=6(x-1)
49=4x(au carré)
-x(au carré)+x-8=-8
2(x+3)+5=6(x-1)
Asked by: USER9397
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135 Answers
Answer (135)
49=4x²
49-4x² =0
(7-2x)(7+2x) = 0
donc
7-2x=0 7+2x =0
-2x = -7 2x = -7
x = -7/-2 x = -7/2
x = 7/2
-x²+x-8=-8
-x²+x-8+8 =0
-x²+x =0
x(-x+1) =0
donc
x =0 -x+1 =0
-x = -1
x = 1
2(x+3)+5=6(x-1)
2x+6+5 =6x-6
2x-6x = -6 -11
-4x = -17
x = -17/-4
x = 17/4
49-4x² =0
(7-2x)(7+2x) = 0
donc
7-2x=0 7+2x =0
-2x = -7 2x = -7
x = -7/-2 x = -7/2
x = 7/2
-x²+x-8=-8
-x²+x-8+8 =0
-x²+x =0
x(-x+1) =0
donc
x =0 -x+1 =0
-x = -1
x = 1
2(x+3)+5=6(x-1)
2x+6+5 =6x-6
2x-6x = -6 -11
-4x = -17
x = -17/-4
x = 17/4