Answer:
![k = 3](https://img.qammunity.org/2021/formulas/mathematics/middle-school/fd6fxw1cxm7fvyum6ouxvc42kaz62va2m5.png)
Explanation:
Given
![f(x) = 0.5x](https://img.qammunity.org/2021/formulas/mathematics/middle-school/i5zlcno3pqpfooo0seyh6w523v1hffwjop.png)
![g(x) = 0.5x - k](https://img.qammunity.org/2021/formulas/mathematics/middle-school/bhkpkm5dgkw0jyzwmpixx9ngpyc9vxas4z.png)
Required
![Find\ k](https://img.qammunity.org/2021/formulas/mathematics/middle-school/qbi4gbnylvgmd0pn7owvpeatba6hsm44e4.png)
Initial expression of f(x) is
![f(x) = 0.5x](https://img.qammunity.org/2021/formulas/mathematics/middle-school/i5zlcno3pqpfooo0seyh6w523v1hffwjop.png)
From the question; we understand that f(x) was shifted down by 3 units;
This implies that
![New\ f(x) = 0.5x - 3](https://img.qammunity.org/2021/formulas/mathematics/middle-school/dvx1or15odl3ooecyiqgdmq1mw6qaats3n.png)
Also from the question; we understand that this new f(x) is equivalent to g(x);
In other words;
![New\ f(x) = g(x)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/mcehmfk1mfohd7u2928bra6wzqkqzyv2xd.png)
Substitute
and
![g(x) = 0.5x - k](https://img.qammunity.org/2021/formulas/mathematics/middle-school/bhkpkm5dgkw0jyzwmpixx9ngpyc9vxas4z.png)
This gives
![0.5x - 3 = 0.5x - k](https://img.qammunity.org/2021/formulas/mathematics/middle-school/1wm3y9yf1n6pw9hpl9frabtyiw2ea73k0p.png)
Subtract 0.5x to both sides
![0.5x - 3 - 0.5x = 0.5x - k - 0.5x](https://img.qammunity.org/2021/formulas/mathematics/middle-school/6i0z3qeznnurk2rtnshebb30uxogc238cg.png)
Rearrange
![0.5x - 0.5x - 3 = 0.5x - 0.5x- k](https://img.qammunity.org/2021/formulas/mathematics/middle-school/qudqeepgyc2wsubjkue84gdx5ffxn7auib.png)
![-3 = -k](https://img.qammunity.org/2021/formulas/mathematics/middle-school/ls0519gnh4wfeqnve5pvr4g89vslaq3t85.png)
Multiply both sides by -1
![-3 * -1 = -k *-1](https://img.qammunity.org/2021/formulas/mathematics/middle-school/f6pqcqqqyvw88lfi5lpofd1yymk7bpeqg6.png)
![3 = k](https://img.qammunity.org/2021/formulas/mathematics/middle-school/gak6x9jptu15cipcekny9h0meejb8j2gjs.png)
![k = 3](https://img.qammunity.org/2021/formulas/mathematics/middle-school/fd6fxw1cxm7fvyum6ouxvc42kaz62va2m5.png)