Question

а) 8x(x-5)-3x(4-2x), если x=-1, b) 7a2+2a(9-5a) если a=2.​

Answer 1

a) 8x(x-5)-3x(4-2x) = 8x2 - 40x - 12x + 6x2 = 14x2 - 52x = 14(-1)2 - 52(-1) = 66
b) 7a2 + 2a(9-5a) = 7a2 + 18a - 10a2 = -3a2 + 18a = -3(2)2 + 18(2) = 24