代數式..英文同數學既勁人請入

add 3 to a 就係 a+3

咁咩係
1. 3 times as large as z??
2. add 6 to the product of 2 and y??
3. divide th product of 5p and 2q by the result of subtracting 3s from r??
4. divide the sum of 2x and 5y by the product of 7z and 3t??

請解呢4題既答應..唔該!!
解左呢4題我就識做哂成份卷- -唔該!