Bonjour !
A = −2 x×(−6 y+4) + 4 x y − x
A = 12xy - 8x + 4xy - x
A = 16xy - 9x
A = x(16 y - 9)
B = 5a + 6b − (3+2a+7b) + 52
B = 5a + 6b - 3 - 2a - 7b + 52
B = 3a - b + 49
C = 4m×(−3 n) + 13 mn + m×(−n)
C = -12mn + 13mn - mn
C = 0
D = 5a² + a×(2a−5) + 10 a
D = 5a² + 2a² - 5a + 10a
D = 7a² + 5a
D = a(7a + 5)
J'espère t'avoir aidé. Bon courage !