Question

Solve for z. 57 = –10z +7

Answer 1

Answer:

z = -5

Step-by-step explanation:

Hi there!

We are given the equation 57 = -10z + 7, and we want to solve for z

In order to solve an equation for a variable, we want to isolate that variable on one side; in other words, we want just z on one side of the equation.

So that means that we'll need to get rid of everything else that's also on the right side. That starts with subtracting 7 from both sides:

57 = -10z + 7

-7             -7

_____________

50 = -10z

Now on the right side, there aren't any other extra terms, but remember: we want just z (also written as 1z, with the coefficient of 1), not z written with a coefficient of -10

If you divide a number by itself, the result is 1. For example. $\frac{3}{3}$= 1. So in order to get a coefficient of 1, let's divide both sides by -10

$\frac{50}{-10} = \frac{-10z}{-10}$

Divide, and cancel:

The zeros cancel out, leaving the equation as:

$\frac{5}{-1} = \frac{-1z}{-1}$

Dividing a number by -1 is pretty much the same as multiplying a number by -1; it simply changes the sign of the number

So 5/-1 will become -5, while -1z/-1 will become 1z, or z

Hence:

-5 = z, or written the other way: z = -5

We found z.

Hope this helps!