Explications étape par étape:
Exercice 1
1)
A.
[tex]2 - \frac{5}{4} \times \frac{1}{10} = 2 \: - \: \frac{5}{40} = \: \frac{80}{40} - \frac{5}{40} = \frac{75}{40} = \frac{15}{8} [/tex]
B.
[tex]\frac{3 - 2}{5} + \frac{3}{10} = \frac{1 \times 2}{5 \times 2} + \frac{3}{10} = \frac{2 + 3}{10} = \frac{5}{10} = \frac{1}{2} [/tex]
2)
(3x – 5)(x – 3)
3x² – 9x – 5x + 15
3x² – 14x + 15
2(3x –1)(–x +7)
2(–3x²+21x+x–7)
2((–3x²+22x–7))
–6x²+44x–14
Exercice 2
2x – 3 = –1
2x = 3–1
2x = 2
x = 1
A toi de faire la b et la c.
Exercice 3
3x +12
3(x+4)
-x² + x
x(-x +1)
(2x –5) ((x–8)+(2x-5))
(2x –5) (x–8+2x-5)
(2x –5) (3x-13)
