Answer :
Answer: [tex]a=-1.3[/tex]
Step-by-step explanation:
1) Reorder the terms: [tex]28 + (-3 * -2 + 5a * -2) = 47[/tex]
[tex]28 + (6 + -10a) = 47[/tex]
2) Solving: [tex]34 + -10a = 47[/tex]
3) Add -34 to each side of the equation: [tex]34 + -34 + -10a = 47 + -34[/tex]
4) Combine like terms: 34 + -34 = 0: [tex]0 + -10a = 47 + -34[/tex]
[tex]-10a = 47 + -34[/tex]
5) Combine like terms: 47 + -34 = 13: [tex]-10a = 13[/tex]
6) Divide each side by -10: [tex]a = -1.3[/tex]