Pls help I'll mark brainliest​

Which simplifys to a+ b? a-(1-b)+1 -(1-a)-b+1 (a--1) -1)+1

Type the correct answer in each box. spell all words correctly. a sequence of transformations maps ∆abc onto ∆a″b″c″. the type of transformation that maps ∆abc onto ∆a′b′c′ is a . when ∆a′b′c′ is reflected across the line x = -2 to form ∆a″b″c″, vertex of ∆a″b″c″ will have the same coordinates as b′.

Urgent need asap △abc is similar to △xyz. also, side ab measures 6 cm, side bc measures 18 cm, and side xy measures 12 cm. what is the measure of side yz ? enter your answer in the box.