Questions on Sample Regression Function about y equals to beta not plus beta i

Danielle earns a 7.25% commission on everything she sells at the electronics store where she works. she also earns a base salary of $750 per week. what were her sales last week if her total earnings for the week were $1,076.25?

Solve the equation by completing the square. x^2+2x=17

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.