Question

2+2





just kidding



(4x+5y)×(9x+7y)
(-7mn)×(-3mn) with method​

Answer 1

21(36m²n²x²+73m²n²xy+35m²n²y²) is the answer.

Expand two brackets at once.

Use FOIL : First Outside Inside Last

(4x+5y)×(9x+7y)=36x²+28xy+45xy+35y²

(-7mn)×(-3mn)=21m²n²

21m²n²×(36x²+28xy+45xy+35y²)

→ 21m²n²×(36x²+73xy+35y²)

→ 21(36m²n²x²+73m²n²xy+35m²n²y²) is the answer.

Answer 2

(4x+5y)×(9x+7y)

=$36x^{2} +73xy+35y^{2}$

(-7mn)×(-3mn)

$=21m^{2} n^{2}$