see explanation
step-by-step explanation:
a
(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )
= 6r + 7 + 13 + 7r
= 13r + 20
b
remove brackets and collect like terms
13 -
r - 1 + r
= 12 -
r
c
remove brackets and collect like terms
= - 8 - r + 2r - 4
= - 12 + r
d
remove brackets and collect like terms
= 7r -
-
- 6r
[-
-
= -
-
= -
]
= r - ![\frac{13}{6}](/tex.php?f=\frac{13}{6})