Question

решите плиз:
1)$( sqrt{t}-3s)*(5s-7 sqrt{t})$
2)$( sqrt{s}-2 sqrt{t})*(4 sqrt{s}- sqrt{t})$

Answer 1

$(sqrt{t}-3s)(5s-7sqrt{t})=5ssqrt{t}-7t-15s^2+21ssqrt{t}=26ssqrt{t}-7t+15s^2\ \ (sqrt{s}-2sqrt{t})(4sqrt{s}-sqrt{t})=4s-sqrt{ts}-8sqrt{st}+2t=4s+2t-9sqrt{st}$