a) 5xy+x+y-2xy-3xy = 5xy-5xy+x+y = x+y = 2+(-3) = -1.
б) (5+a)(b-6)-ab+6a = 5b-30+ab-6a-ab+6a = 5b-30 = 5×7-30 = 35-30=5.
в) 4a(b-c)+4ac = 4ab-4ac+4ac = 4ab = 4×v3×2v3 = 8×(v3)² = 8×3 = 24.
a) 5xy+x+y-2xy-3xy = 5xy-5xy+x+y = x+y = 2+(-3) = -1.
б) (5+a)(b-6)-ab+6a = 5b-30+ab-6a-ab+6a = 5b-30 = 5×7-30 = 35-30=5.
в) 4a(b-c)+4ac = 4ab-4ac+4ac = 4ab = 4×v3×2v3 = 8×(v3)² = 8×3 = 24.