Question

Suppose that y = 5 x plus 4 and it is required that y be within 0.005 units of 8. For what values of x will this be​ true?

Answer 1

0.795
`\leq` y
`\leq` 0.805

Explanation:

8 = 5x + 4

5x = 4

x = 4/5 or 0.800

therefore 0.800 + .005 and 0.800 - .005 =

0.795
`\leq` y
`\leq` 0.805

Answer 2

so we have an inequality for y -

7.995<y<8.005

Then now we need in inequality for x

(y-4)/5 = x

so that means that so if we have (7.995-4)/5 we get 3.995/5 = 7.99

so we have our first 7.99<x<b

Now we solve for b

So that means that 5.005/5 = 1.001

since we are changing it we switch our signs

from 7.99<x<1.001

we do 7.99>x>1.001

therefore

1.001<x<7.99