Please help

solve the following

4x-3=2x+7

2x+6=7x-14

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

Find the area of the triangle formed by the origin and the points of intersection of parabolas y=−3x^2+20 and y=x^2−16.

Jonathan can type 20 documents in 40 minutes ,and susan can type it in 30 minutes and jack can type it in 24 minutes working together ,how much time will it is take them type the same document