Mrs. Simpson's class has 10 girls and 15 boys. What is the ratio of girls to boys?

Compare these two waves: the blue and orange waves have the same pitch, but the blue wave is louder. the blue and orange waves have the same volume, but the blue wave has a higher pitch. the orange wave has a higher pitch, but the blue wave is louder. the blue wave has a higher pitch, but the orange wave is louder.

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

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