7. Раскройте скобки и приведите подобные: a) -3(-4x+4)-9(4x-7); б) -3(-4x+4)+9(4x-7); в) -3(-4x+4)-9+(4x-7); г) (-4x+4)-(4x-7); д) (-4x+4)+(4x-7).

a) \(-3(-4x+4)-9(4x-7) = 12x - 12 - 36x + 63 = (12x - 36x) + (-12 + 63) = -24x + 51\) б) \(-3(-4x+4)+9(4x-7) = 12x - 12 + 36x - 63 = (12x + 36x) + (-12 - 63) = 48x - 75\) в) \(-3(-4x+4)-9+(4x-7) = 12x - 12 - 9 + 4x - 7 = (12x + 4x) + (-12 - 9 - 7) = 16x - 28\) г) \((-4x+4)-(4x-7) = -4x + 4 - 4x + 7 = (-4x - 4x) + (4 + 7) = -8x + 11\) д) \((-4x+4)+(4x-7) = -4x + 4 + 4x - 7 = (-4x + 4x) + (4 - 7) = 0x - 3 = -3\)