WILL GIVE BRAINLIEST!!! Distributive property quick check. Simplify: 1/2 (6z+10). Simplify: 10(5+2x). Simplify: 3(5y+6)-4. Simplify: (3a+2)(4).

Acompany that manufactures and sells guitars made changes in their product range. from the start they had 20 models. then they reduced the number of models to 15. as a result, the company enjoyed a 10% increase in turnover. - how much did the stock level change? in (%)

Can someone me out here number 4 plz

If set d is not the empty set but is a subset of set e, then which of the following is true? d ∩ e = d d ∩ e = e d ∩ e = ∅