Réponse:

BNJ

Explications étape par étape:

[tex]a)8x = 20 \\ x = \frac{20}{8} = \frac{5}{2} \\ b) \: \: 12 = 5l \\ \frac{12}{5} = l \\ c)30 = 25t \\ \frac{30}{2.5} = t \\ 12 = t \\ d)x + 7 = 20 \\ x = 20 - 7 = 13 \\ e) \: y - 12 = 3.5 \\ y = 3.5 + 12 = 15.5 \\ f) \: \: 4. 2 = 8z + 1.6 \\ 4.2 - 1.6 = 8z \\ 2.6 = 8z \\ \frac{2.6}{8} = z \\ g)14 = 5t - 48 \\ 14 + 48 = 5t \\ 62 = 5t \\ t = \frac{62}{5} [/tex]

salut

a) 8x = 20

x = 20/8 = 5/2 b) 12 = 5l

12/5 = l

c) 30 = 25t

(3U)/2.5 = t

12 = t

d) x + 7 = 20

x = 20 - 7 = 13 ) y - 12 = 3.5

y = 3.5 + 12 = 15.5

f) 4.2 = 8z + 1.6 4.2 1.6 82 2.6 = 8z 2.6/8 = z

g) 14 = 5t - 48 14 + 48 = 5t 62 = 5t t = 62/5