ANSWER
[tex]a = \frac{5}{16} [/tex]
EXPLANATION
We want to find the value of a for which the binomial, 2a-1 is smaller than the value of the binomial 7-1.2a by 7.
This means that, when we subtract 2a-1 from 7-1.2a, we should get 7.
[tex]7 - 1.2a - (2a - 1) = 7[/tex]
Expand:
[tex]7 - 1.2a - 2a + 1= 7[/tex]
Group similar terms:
[tex]- 1.2a - 2a = 7 - 7 - 1[/tex]
[tex] - 3.2a = - 1[/tex]
Divide both sides by -3.2,
[tex]a = \frac{ - 1}{ - 3.2} [/tex]
[tex]a = \frac{5}{16} [/tex]