As with any triangle, the sum of angles is 180°.
(a)
(x -5) +(3x +30) +35 = 180 . . . . . sum of angles is 180
4x +60 = 180 . . . . . . . . . . . . . . . . collect terms
4x = 120 . . . . . . . . . . . . . . . . . . . . subtract 60
x = 30 . . . . . . . . . . . . . . . . . . . . . . divide by 4
(b)
Angle A = x -5 = 30 -5 = 25
Angle B = 3x +30 = 3*30 +30 = 120
He paid 3.19 per gallon both times......first time he bought 12.53 gallons....next time he bought 11.86 gallons
so ur expression is : 3.19(12.53 + 11.86)
Answer: Associative property
Step-by-step explanation: it is the same equation but they switched the numbers around on the other side of the equal sign so therefore its associative property
