Answer:
a) -11
Step-by-step explanation:
[tex]\frac{3 + x}{4}[/tex] = [tex]\frac{x + 1}{5}[/tex]
transpose
5 (3+x) = 4 ( x+1)
15 + 5x = 4x + 4
5x - 4x = 4 - 15
x = -11
You can even cross-check
a . -11
[tex]\frac{3 + (-11)}{4}[/tex] = [tex]\frac{-11 + 1}{5}[/tex]
[tex]\frac{3 - 11}{4}[/tex] = [tex]\frac{-10}{5}[/tex]
[tex]\frac{-8}{4}[/tex] = -2
-2 = -2
CROSS-CHECKED
