Resposta:
Insolamos a variavel.
1)
a)
[tex]4x - 7 = 1 \\ \\ 4x = 1 + 7 \\ \\ 4x = 8 \\ \\ x = \dfrac{8}{4} \\ \\ \Large \boxed{ \green{x = \bf 2}}[/tex]
b)
[tex]x + 2 = 5 \\ \\ x = 5 - 2 \\ \\ \Large \boxed{ \green{x = \bf 3}}[/tex]
c)
[tex]2y - 4 = 2 \\ \\ 2y = 2 + 4 \\ \\ 2y = 6 \\ \\ y = \dfrac{6}{2} \\ \\ \Large \boxed{ \green{ y = \bf 3}}[/tex]
d)
[tex]2a + 4 = - 6 \\ \\ 2a = - 6 - 4 \\ \\ 2a = - 10 \\ \\ a = - \dfrac{10}{2} \\ \\ \Large \boxed{ \green{ a = \bf - 5}}[/tex]
e)
[tex] - 2 + 5y = 13 \\ \\ 5y = 13 + 2 \\ \\ 5y = 15 \\ \\ y = \dfrac{15}{5} \\ \\ \Large \boxed{ \green{y = \bf 3}}[/tex]
f)
[tex]x + 1 = 3 \\ \\ x = 3 - 1 \\ \\ \Large \boxed{ \green{x = \bf \: 2}}[/tex]
g)
[tex]2x - 3 = 8 \\ \\ 2x = 8 + 3 \\ \\ 2x = 11 \\ \\ \Large \boxed{ \green{ x = \bf \dfrac{11}{2} }}[/tex]
h)
[tex]4 - 9x = 2 \\ \\ 4 - 2 = 9x \\ \\ 2 = 9x \\ \\ 9x = 2 \\ \\ \Large \boxed{ \green{ x = \bf \: \dfrac{2}{9} }}[/tex]
i)
[tex]3z - 7 = 12 \\ \\ 3z = 12 + 7 \\ \\ 3z = 19 \\ \\ \Large \boxed{ \green{z = \bf \dfrac{19}{3} }}[/tex]
[tex] \Large \boxed{ \bf \blue{ \underline{Bons \: Estudos!}}}[/tex]