3(x + 4) = 18 (Given)
3x + 12 = 18 (Distributive Property)
3x = 6 (Subtraction)
x = 2
Give a reason for the last step in the argument shown.

Answer :

GivEn - 3(x+4)=18

(when we expand it using Distributive property) - 3x+12=18 (and when we change the side of 12 and subtract it from 18 , it becomes) - 3x=6and then we have to change the side of 3 and bring it to RHS and as it is multiplied with x in the the LHS ,in RHS it will be divided with 6 in RHS ,thus it will form the equation = x=6/3 ,which when simplified becomes ,2 . Thus , our answer is 2.

This polygon has 4 sides
180(4-2) = 180(2) = 360 degree
80+90+2x + 3x = 360
170+5x = 360
5x = 190
x= 38
measure of angle t is 2(38)= 76
the answer is c. trust me
hope this !