Option 1. The equation that represents the direct variation that exists between a and b is b = –a.
The direct variation is of this form y ∝ x
This gives the equation
y = kx
The constant is k
From our question we have
b ∝ a so b = ka
b = [tex]2\frac{3}{4}[/tex]
a = [tex]-2\frac{3}{4}[/tex]
Remember that b = ka
[tex]2\frac{3}{4} = -2\frac{3}{4} k[/tex]
This would cancel out to
1 = -k
or k = -1
Hence the equation would be written as
b = -a
Read more on direct variation here:
https://brainly.com/question/9983911
#SPJ1