If g(x)=4(x-5), find the value of x if g(x)=8

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Apackage of five erasers cost 0. $.39 at this rate how many how much would 60 erasers cost in dollars and cents

Match the scale and the actual area to the area of the corresponding scale drawing. scale: 1 inch to 4 feet actual area: 128 square feet scale: 1 inch to 7 feet actual area: 147 square feet scale: 1 inch to 8 feet actual area: 256 square feet scale: 1 inch to 5 feet actual area: 225 square feet area of scale drawing scale and actual area scale drawing area: 3 square inches arrowright scale drawing area: 8 square inches arrowright scale drawing area: 4 square inches arrowright scale drawing area: 9 square inches arrowright