If it' 6²
(5x-1) (6²+3x+7)
= (5x-1)(3x+43)
= 15x² -3x+215x-43
=15x²+212x-43
if it's 6x²
(5x-1)(6x²+3x+7)
=30x³+15x²+35x-6x²-3x-7
=30x³+9x²+32x-7
