Answer
$10y^{2}-19y-15$
Work Step by Step
Step 1: A Special Product cannot be applied here. In its place, we will use the FOIL method.
Step 2: $(5y+3)(2y-5)=5y(2y)+5y(-5)+3(2y)+3(-5)$
Step 3: $5y(2y)+5y(-5)+3(2y)+3(-5)=10y^{2}-25y+6y-15$
Step 4: $10y^{2}-25y+6y-15=10y^{2}-19y-15$
Step 5: Therefore, the required expression is $10y^{2}-19y-15$
