Dau coroana!!!!Ajutati ma va roooooooooog!!!!!

Răspuns:
a.
a/4=7/2b
2ab=4×7=>ab=28:2=>ab=14
a²b²-3ab+5=14²-3×14+5=196-42+5=159
b.
u/6=10/3v
3uv=10×6
uv=60:3=>uv=20
2×uv²-uv/5+6=2×20²-20:5+6=800-10+6=802