So we have the equation:
[tex] \frac{z+9}{4}=2.1 [/tex]
Then we need to multiply by 4 on both sides to get rid of the denominator on the left:
[tex] z+9=8.4 [/tex]
Then we subtract 9 on both sides to solve for z:
[tex] z=-0.6 [/tex]
Therefore the answer is z = -0.6.
